[Sony Xperia C5 Ultra] scpion:
First off, I am not a technical guy. So this review is purely based hand on feel of this device. Since there are not much online reviews around, Hope this helps to address some concerns u may have before taking the plunge. Cheers!

Unboxing,

Nothing out of the ordinary..

Cheap headset, 850mah charger (WTF Sony..), usb cable. Some menu and paper.

Build quality,

Very pleased. Though plastic, it really doesn't feel cheap AT ALL. Everything is solid, no creaking whatsoever. Very comfortable in the hand. Especially when its not as wide as other 6' incher. One thing I notice.. Normally when we hold a phone, it will be more to the bottom. Even though the weight is evenly distribute, Its a tall phone. So, it can feel "top heavy" and tip over if u do not hold properly..I got the white version, I think it makes the bezel-less display stands out. Buttons are clicky enough, minus my camera button.. The flap covering the nano sim and sd slot is very very flimsy though but fits securely. Just dun play with it too often....

Screen,

Fantastic built quality. I cant see individual pixels even up-close. Good viewing angle. Bright, even in bright daylight with the sun shining directly on it. Screen has a oleophobic coating so it really smooooth. Very responsive to the touch.

One thing that seriously bug me though is the colour calibration. Its is extremely washed out by default. (I read there are 2 different supplier for the screen with different quality.) U will have to play with the white balance to really find the suitable colour combo. I tried playing the same video, photos on other devices to confirm my findings. Even after some tweaking, colours are still a little off as the contrast is slightly on the lower side. Seriously, I almost flipped when I first played the sample landscape video, Its the worst I have ever seen.. there's no colour at all.. everything looks pale. Hopefully an update will solve this issue. Another strange behaviour I notice is the white balance setting. After a reboot, white balance will go back to factory default. Only when u open up the white balance app, the settings are applied. The settings do sticks, but just not applied automatically after a reboot.

Camera, I am not a very trigger happy person...

This is one area I think Sony keeps screwing up.... Most photos on Superior Auto are overly overly overly exposed. Leaving washed out and pale colours. Details are there though. Noises fortunately are keep very low in dim light. Performance are pretty much the same on both the front and back camera. Manual mode produce more accurate pics with some manual adjustments. Ironically, I find that the stock google camera from playstore produce better results. So I think it is Sony that is messing up their processing algorithm.. I not tried tried video yet......

They have a dedicated 2 step camera button. I think mine is kinda faulty. Its difficult to press to focus, impossible to follow through to take the shot. I have to use my nails to really press the button. I have to check this out on the other sets in the store.

Battery,

So far pretty good.. I brought it home and charge up to full with a 1.5A charger. Took around 2.5-3 hrs from 30% to 100%, a little too long I thought. After around 8hrs up time, Wifi on, Lte on, 2hr 55min screen on time, I am at 49%. Pretty good I would say.

Phone,

Not thoroughly tested.... Fatal flaw..... see below.

Speaker,

Extremely loud! The single speaker is located at the bottom grill and its front facing. Hooray!! Sounds came out quite decent and clear without distortion even at max.. Its..really.. loud...

Performance,

Really snappy in real life usage. Have not experience any lag or slowdown yet.. I am currently using S4 i9506(a S800 version), Z ultra and Z3TC. This "mid-ranger" beats all of them with an average of 46000 on antutu 64bit test.... Average FPS in Epic Citadel is 43.3. Quadrant standard is at around 20000. Device stayed relatively cool throughout without abnormal overheating experienced.

GPS,

No Issue. Position lock on GMaps in less than 5 sec cold start.

So far, I am happy!:D

Just my 2cents worth.

Edit - After one day, I notice that the screen will flicker whenever its trying to load a video preview. Happens everytime in facebook and the default album app.

Another serious flaw is that when I make a phone call, the microphone is activated at the earpiece's side rather than at the mountpiece. Making hearing on the other end very soft and a giant pain in the ass... Ironically, on my virgin call, I found this out when I called Sony to complain about my camera button and they couldnt hear me properly.. Seriously... Sony WTF...?????

Factory reset solved the above problem.:)

F U Sony, after 2nd call, the mic problem is back!