[Device Reviews and Information] Ouzo:
Thanks to the mods for moving this. Sorry i posted it in the wrong place - oops!

Hey everybody. In a blatant and self serving attempt to try and cultivate interest and support in a phone that I have just purchased, I thought I would post a mini review here with a little bit of info ;)

Seriously though, if, like me, XDA as usually your one stop shop for everything phone related and you're considering buying one of the many offerings available directly from China these days, getting the right info can be hard. Sure, some info is available on other sites, but often online translation tools are necessary and it's hard to get a clear picture of what you can really expect from a prospective purchase.

I've been reading about various Chinese devices for over a year now, quietly waiting until I was sure I could get a reasonable level of performance for my money before buying one, all the while nursing my ageing HTC Sensation through daily use. I have a Samsung Galaxy Note 2 as well, but that has a broken screen so it is purely used as a mini media PC connected to a TV these days. I also have an Nvidia Tegra Note that offers great performance at a very reasonable price.

I am uncertain how much waffle you guys will want to wade through so I'll list some basic specs and then provide a few pros and cons as I see them, plus a few very basic tips that I've stumbled on in the first week, some of which will apply to similar devices that use vey similar ROMs. If you want more info, please ask.

Forum member oxiroxt has had a fairly mixed experience with their G4S, including hardware problems. details are in post 1175 here: http://xdaforums.com/showpost.php?p=59463919&postcount=1175

Here are the basic specs:

Jiayu G4S -

16GB ROM 2GB RAM - MediaTek Octacore A7 MT6592 SoC @1.7Ghz with Mali 450 GPU.

Dual sim card standby (one Micro SIM Card)

GSM 900/1800MHz (see screenshot below of MTK Engineer Mode which shows more bands available, including GSM850 - I haven't tested this band though)

WCDMA 900/2100MHz

Android OS: 4.2.2

4.7 inch, IPS multi points corning Gorilla II OGS touch Screen (I have my doubts about the Gorilla Glass as I have a couple of small scratches already)

Camera: Front camera 3.0 Megapixels. Back camera: 13.0 Megapixels with CMOS flashlight, auto focus

Stereo FM Radio

Gravity Sensor, Proximity Sensor, Light Sensor

3000mAh battery

Dimensions: 133×65×10(mm)

What's in the box:

1 x Phone

1 x Battery

1 x AC Charger Adapter

1 x USB Cable

Pros:

Price - Only £137 delivered to UK via DHL - price is falling all the time at the moment too.

Screen - Pleasing colours, better outdoor visibility than I expected.

Call quality - good, with noise cancellation microphone on rear of device (call quality better than HTC Sensation)

Performance - over 27,000 points in Antutu, nice and fluid in use. Not as quick as Tegra Note or Snapdragon 800 of course

Battery life - over five hours of screen on time in a sixteen hour period, with 37% battery remaining. I have hit eight hours of screen time twice.

Build quality - less creaky than my Note 2

Supports USB OTG

Supports USB Mass Storage when connecting to PC

Compact size - at only 65mm wide, one handed use is practical for most people.

GPU performance is not great - only two thirds of the Samsung Galaxy S4, but it's ok for Modern Combat 4. It scores 61FPS on in Epic Citadel on high detail setting (Ultra High setting unavailable).

Pre-rooted - Root can be toggled under Settings/Security (love this feature in a stock ROM)

SD card slot

Dual SIM

Removable battery

Notification Light - three colour, RGB

Cons:

Lack of developer support here on XDA for now

No MHL for TV out

Caller ID mismatch bug

Camera below expectations - certainly worse than tweaked HTC Sensation camera

Possible wifi bug - affects things like wireless streaming if the screen is off

Deodexing ROM to work with files not 'standard' procedure

GPS - connects quickly but accuracy is still behind Qualcomm's efforts these days (much better than the old HTC Touch Pro/Raphael though!!)

Internal SD only approx. 9GB with internal storage just under a further 4GBs (It should be possible to repartition this by altering EBR1 and EBR2, but I haven't tried. iOcean have done this on their latest ROM for the X7S, decreasing phone storage to 1GB and increasing internal SD card to about 13GB - May 2014).

Screen has some backlight bleeding around bottom edges - sensitivity slightly lower than I'm used to but by no means bad.

Most sites claim 64GB Micro SDXC support - this is wrong, exFAT is not supported so you'll need to format the card to Fat32 for it to work.

English US - if you're in the UK and you change the language to English, you'll be stuck with US English language and location. To get around this you will need to toggle root on in settings/security, download Morelocales2 from the Play Store and then use it to change over to EN GB. I've edited the build.prop too.

Xposed - doesn't work at the moment due to the way the ROM is compiled (if I've understood correctly). Head over to that thread for basic details of a workaround to deodex the ROM, or download one of the customs ROMs based on stock that has been deodexed.

No 4G

Buttons are not backlit

There were issues with Facebook and Whats App but apparently all is now OK - sorry I don't use these so I haven't tried. Earlier versions of Facebook apparently work.

Recovery, Drivers for PC, Flash tools etc:

Jiayu.es app - Recoveries and tools are available from several sources, but at the time of writing the easiest way now is to download the Jiayu.es app. This now has downloads for the stock recovery, CWM, Stock ROM (European version with ASOP keyboard as opposed to Baidu which comes on the phone if you buy directly from China) as well as drivers for PC and the necessary tools to flash the ROM from a PC.

Mobile Uncle Tools - I used this to flash CWM recovery and tweak a few things before I discovered the Jiayu.es app. You can use this to back up your IMEI (NVRAM) which I highly recommend as the loss of IMEI is something I have read about frequently when people are flashing similar devices.

ROMs:

Before flashing any ROMs, I recommend using MTK Droid Tools to create a backup of your device on your PC. This includes backing up your IMEI number and every other partition. If you hit trouble you can restore your device to factory fresh. Head over to gizbeat for a tutorial and video.

Unfortunately at the moment I don't have time to try lots of ROMs (boooo!) which is frustrating, but it's also a mark of the fact that I'm just able to use the Jiayu stock ROM without too many compromises.

As the device gains in popularity there are now more an more ROMs appearing in various forums around the web. At the moment, there are a few basic choices to make. First, there are the stock ROMs 'officially' released by Jiayu. The stock ROMS are installed using SPFlashtools. Secondly there are deodexed versions of the stock ROMs that will allow you to run the Xposed framework and mods like the excellent Gravitybox. Thirdly there are ports of other ROMs, such as MIUI of ColorOS. The last two types will be installed through recovery, for which you need a custom recovery such as CWM.

One of the stock ROMs as well as both a stock recovery and CWM Recovery are available through the Jiayu.es app.

For me, the main source of ROMS remains NeedROM. There are now several recoveries, the stock ROM as well as ports of MIUI, ColorOS, YunOS and so on. This is the place I usually check first as the site is well organised and in English which makes it easier for me: http://www.needrom.com/phone-roms/jiayu/g4s/

There are now a number of ROMs available here, including at least a couple of MIUI here:

http://www.592zn.com/ (use Google Translate to browse the site if needed and to find the threads relating to the Jiayu G4S ;)

Jiayu forum:

http://bbs.ejiayu.com/forum-184-1.html

Some of mite_jan's posts with recommendations/ROM related links (press thanks if you appreciate his links):

http://xdaforums.com/showpost.php?p=52989103&postcount=50

http://xdaforums.com/showpost.php?p=53133246&postcount=90

http://xdaforums.com/showpost.php?p=53270549&postcount=134

http://xdaforums.com/showpost.php?p=53284249&postcount=141

http://xdaforums.com/showpost.php?p=53361043&postcount=180

Two Hidden Tweaks in ROM:

1. A limited set of developer options was already available in settings when I first booted my G4S (Stay Awake, USB Debugging, Allow Mock Locations), but if you want access to the whole lot you can repeatedly tap the Android Version section under Settings/About Phone. This will take you straight to the developer options page. By default all animations are turned off so I used this to turn them on. You will still only have access to limited developer options once you exit this page, so you will have to get tapping the next time want to go back into it.

2. An 'Advanced Settings' option in Settings menu will appear if you repeatedly tap the Build Number under Settings/About Phone. This new menu allows you to tweak the transparency separately for lockscreen, main interface and the status bar itself. There's also and option to toggle the volume key wake feature, but this doesn't do anything for me - the volume buttons always wake the phone.

General Blurb:

So far, I feel like my money has been well spent, though I'm only a week into ownership. The screen in particular has exceeded my expectations with pleasant colours and reasonable outdoor visibility (better than HTC Sensation, but not great). Whites look 'white' as opposed to having the slightly yellowy hue that has affected all the devices with AMOLED screens that I've used, not to mention the poor offering on my Tegra Note. There's more backlight bleeding around the edges than I would like though which is a pity. This is certainly not the case with all Chinese devices - the iOcean X7S, for example, has a much better screen from that point of view. Call quality has exceeded my expectations and, as with other similar devices, the firmware offers various ways to manage the dual SIM functionality. As well as binding specific contacts to a particular SIM, you can also independently choose which SIM is used for SMS, voice calls, data and video calls. You can also be prompted to choose which SIM to use on the fly each time if you prefer. Only one SIM can use WCDMA at a time, but you can choose which SIM that is without physically swapping the SIMs or rebooting the phone. I thought battery life might be poor with two SIMs in, especially as I live in a marginal area for one of the networks I use, but so far battery life has been pretty good in general use. I was surprised to get over five hours screen time and still have well over 30% battery left. Intensive games and videos can drain the battery more quickly though of course.

Build quality also appears to be pretty good for a budget device. It's certainly less creaky than my partner's Note, my Note 2 and any other number of Samsung devices that I've used. The petite dimensions are also great. The thickness of 10mm simply isn't an issue for me, especially given the generous battery under the hood. For the first week there were no noises from it at all, though there is a tiny creak from one corner of the battery cover now after many many cycles of removing and replacing it as a result of messing about with it.

The main issues I've faced so far are the fairly weak 13MP camera that introduces a lot of noise and offers poor detail in spite of a wide range of tweaking options within the app itself and a caller ID mismatch bug revolving around MIN_MATCH criteria . The latter means that if you store a contact's telephone number in domestic format (e.g. 07707 123456) then send them a text message, any reply you receive from them will be prefixed with the international country code and will be put into a separate thread. If you store their number with the international dialling code, when they call from the same country, the phone will not recognise their number. So far the easiest bodge is to store both formats for each contact, then remember to send SMS to the number will international prefix. Both these issues are deeply annoying from my perspective. See here for an explanation of the caller ID problem: http://xdaforums.com/showthread.php?t=2268120

There does also appears to be a bug with wifi - if you stream films wirelessly to your TV the screen will have to remain on, which is the first time I've had this issue.

Performance is genuinely fluid if not up to Tegra 4 or Snapdragon 800 standards, but it's certainly better than the Galaxy Note 2. The one area that confuses me is GPU performance. I very briefly had an iOcean X7S which has the same SoC but a 1080p screen rather than the Jiayu's 720p. To my surprise the Jiayu actually scores lower in Antutu in this area. My guess is that either this is a SoC from a different BIN compared to those going into the 1080p devices, or something else is going on to artificially limit performance. On balance, for the money, performance is fantastic and is better than other phones being offered in the UK from retail outlets at over twice the price. Personally I miss some of the features of HTCs Sense based ROMs, but not enough at the moment to shell out over £500. This is now my daily driver and unless it dies prematurely I think I'll have it for up to a year (dependent upon whether or not I get fed up with the camera). Within a year my gut feeling is that similar devices with 4G will be ready for main stream adoption :) In much the same way that sections of the motorcycling community enjoy having a flagship bike and a small capacity run around to hack, tune and mess around with, I kind of hope more XDA users will start to buy devices like the Jiayu G4S and mess around with them. I know MediaTek have been useless at releasing the source code which is a massive stumbling block, but we can still have a bit of fun with them, eh?

*UPDATES*

Battery life - on one occasion I reached just under 35 hours of up time, with 7 hours 52 minutes of screen time, with 9% battery left. Usage was a mix of a few phones calls, some text messages, two email accounts, web browsing, about thirty minutes of Shadowgun, around an hour of streaming music via A2DP and about two hours of listening to music on headphones.

Multi tasking is good when web browsing and listening to music (as it should be). Playing a game like Shadowgun whilst using a Moga Pro controller AND streaming music via Bluetooth is also absolutely fine.

Bluetooth - Bluetooth range is better than on my Tegra Note, HTC Sensation and Note 2 when streaming music. The actual quality of audio via Bluetooth is not the best. It's noticeably worse than the Note 2.

Audio quality out of the headphone jack is also not great. The built in equaliser helps a lot, but it really doesn't sound much better than Bluetooth to me.

Camera - somehow, I have dust inside the outer lens already (the outer lense being part of the sealed camera unit). UPDATE I hovered the dust out!!

As for the images themselves, I've found setting sharpness to maximum and turning off face beautification helps improve images a bit. User 'coffee' over at MTKForums.com reckons the Camera FV-5 app is great at getting the best out of the sensor in the G4S, especially if you save the images in lossless PNG format. I haven't tried it yet.

GPS - after using GPS Test to get the first lock (go outside, set the option within the app to keep the screen on and update AGPS data), subsequent locks have usually been very quick. Unfortunately accuracy in apps like Co-pilot has been very hit and miss for me. On a few occasions my location is shown on an adjacent road that is over 50 metres away. In one instance restarting the device solved the problem. I've recorded a few tracks whilst cycling using Endomondo Pro and these have been fine apart from one occasion where I stopped and went in a shop and it added a mile onto my journey!

Notification LED - this is a three colour red, green, blue unit, so you should be able to set the colour for different notifications using a third party app. I haven't tried this yet.

Charging bug - the LED will glow green when the battery is only 90% charged. The iOcean X7S has exactly the same issue.

Text/Font not being visible - if you can't see text in certain apps (Such as Titanium Backup), open the Themes app and switch to the 'System' theme.

Wired Headset - I don't have the official Jiayu Headset but I've tried Samsung and HTC's more recent offerings. The play/pause button on the Samsung headset works, but the volume buttons skip tracks instead. Play/pause works on the HTC headset, as do next/previous track, but fast forward and rewind do not. I haven't tried making calls with them yet. As there are a couple of different standards for four pole 3.5mm headsets that each have the 'ground' and 'microphone' in different positions, you will need to have the right type for the correct functionality.

USB OTG - In addition to flash drives and a small bus powered 80GB hard drive, I've also tried a 1TB WD Passport Ultra formatted to fat32 (also bus powered). Unfortunately the G4S was unable to power it. Some other devices such as a Samsung Galaxy Tab 3 are able to. If you connect the drive to a powered USB hub, then connect the hub to the phone it works fine.

ROM UPDATE 20140422-121442 - For me, the caller ID bug remains :( To be more exact, if I text someone using the national telephone format (e.g. 07707 123456), when they respond the message is sent with the international dialling prefix (+44 for example) and their SMS will be placed in a different thread.

This ROM uses the same format that original phones imported from China have, i.e. it comes with Baidu IME input as opposed to the one available from Jiayu.es which has the ASOP keyboard. There are a few other differences between the Chinese and Worldwide releases. The kernel and radio etc are the same as the last two releases. I used the ext4_unpacker tool available here on XDA to have a look inside the system.img of the new release and the old release, and I think many of the libs are the same too.

One small bug that seems to be fixed is that call history times in the dialler now displays properly, rather than being obscured by other parts of the dialer.

The volume key wake toggle option in the advanced setting area still does not work (you can't prevent the volume keys from waking the phone).

With most of the themes, the problem where text in some apps is invisible remains the same. Use the 'System' theme to get around this.

USB OTG.....continued - Sadly the CSL DVB-T mini Android TV Stick doesn't work with the G4S out of the box.

FIX - First, turn on superuser/root access in settings/security. Then download Chainfire's USB Host Diagnostics from the Play Store. Run the app, then hit Start Diagnostics. You will be prompted to plug in a USB OTG device. I used a OTG adapter and a memory stick. After the diagnostics have run and you have been asked whether or not you want to upload the results, you will be prompted that USB OTG is not working and that it might benefit from attempting a fix. Let it run the fix and then reboot the phone. The CSL TV dongle will now work :)

I guess this will probably also help with other USB OTG problems you might encounter.

http://www.amazon.co.uk/CSL-Receiver-Smartphones-Interface-Smartphone/dp/B00DZR3OKS#productDetails

Sample photos courtesy of user ykassana http://mtkforums.com/viewtopic.php?f=5&t=842