[T-Mobile Galaxy Note 4 Android Development] AlkaliV2:
A Proper Review for CM12 12/20/14 Build Posted by Slayher

So I felt it was important with so many people asking about the performance of this ROM that I address it by installing myself and putting it through its paces. This is my review of the CM12 Release found in the OP 12/20/14 build.

Basic Functions

Phone calls work for me without reboots, volume level is backwards for phone calls and speaker phone (buttons control the direction properly, but max volume is minimum and minimum volume is maximum) however volume works properly in media applications. Text messages arrive quickly, I have good LTE signal for my area and it connects immediately when I leave my Wi-Fi range, bluetooth has been connected to my Pebble for over 12 hours without a single drop, and I don't use or need NFC but the option doesn't exist to turn it on as I can find. GPS worked for me without issue and got a lock on my home almost immediately without tweaks using Google maps. The notification light works well, you can set it to several speeds in the settings menu per your preference.

Overall it performs just like a phone should and while it needs some tweaks overall it is quite good in this category.

Software

I used the CM12 Gapps (20141109) from basketbuild and I had no issues during install or boot-up. Total system with that Gapps installed was 1.2GB and I removed some Google applications (YouTube, Maps, Google+, etc.), put them in user apps, and got it down to 889MB. The performance is excellent for all apps and I've only had one app crash so far and it was because I was harassing Google Music to use Viper4Android. There is no "Sound Effects" option to choose Viper so you'll have to freeze AudioFX to make Android use it by default. I've been using the stock browser and other than having to accept logins 4 times in a row it is completely stable and works very quickly. I use chompSMS as my messaging service and it has worked properly for all things I've tried including MMS. No group messaging test yet, someone else will have to fill that in. Ambient display seems to work okay, it comes on when you pick up the phone like it should, but just leaving it alone on the table it seemed to flash the screen on randomly every few seconds. Since the notification light is flashing you probably won't need ambient display, but it needs some work so it doesn't keep turning the screen on and draining the battery.

Performance

I'll lead with the only lag I am seeing, because it is the lag most people would see, and that is from turning the screen on. The buttons light up a half a second before the screen comes and it takes roughly one second for the lock screen to appear. I tried to remedy this by turning off Ambient display but the lag persists. I'm sure that this is fixable and should not detract from the overall speed of the rest of the system. Everything else opens very quickly and I would venture to use the word immediately for the apps you use most. Very impressed with application speed and overall phone responsiveness.

Battery Life

(Screenshots below)

Ah yes, what everyone wants to know about. How is the battery life exactly? Well, it depends. Ha! People hate that answer. Keep in mind I do not have battery saver active. Tracking my usage this today with bluetooth on connected to my pebble, a mix of Wi-Fi and LTE signal, and some regular texting I am losing a between 1.1% and 2.2% per hour based on my usage. I've had it unplugged 9 hours so far and lost 20% of my battery with very little screen on time. So here is the deal, based on my personal research there is no excessive battery drain on this build. In fact, this is the most responsible use of Google Services I've seen in the history of me owning an Android phone. I've attached screenshots and stats below so you can see what I mean. Touchwiz may have better screen on time, but better deep sleep goes to CM12. Will there be a time when CM12 can offer both? Of course, as the build matures it will get closer and closer to the performance level of Touchwiz and could potentially exceed it because there are far less apps phoning home.

Issues I Had

I installed this 12/20 ROM twice and the first time I installed it I was getting random reboots. It was happening during app installations and during setting changes. I went back and wiped everything, including internal memory and I've had no reboots on my second install. However, don't use TWRP to fix permissions after installing and rebooting into CM12. It wouldn't boot after fixing permissions with TWRP so that is just a heads up. As mentioned before the volume indication is backwards on this build (12/20) for in-call volume and speakerphone volume. There isn't a settings menu option to turn on/off the softkey lights as of yet, there isn't a sound effects menu (and there might not ever be, I don't know I haven't seen official 5.0 yet), and ambient display seems to arbitrarily turn on at the moment. There is also an issue with assigning the correct time zone to device automatically and it kept changing my time. However, putting my timezone in manually made it work and led to an easy fix. But these are minor quibbles. I'll update this section as I continue to test.

Final Thoughts

Who is this build for?

People who love testing new ROMs, people who want to try out Android Lollipop because they are tired of waiting on Samsung, lovers of Cyanogenmod, lovers of AOSP, and anyone who likes very responsive and bleeding edge software. Fattire makes an excellent point with, "I'd add also anyone who's worried about Carrier IQ installed on TouchWiz."

Who shouldn't use this?

People who use their phone for business, people that use their phone for travel, power users looking to game for 6 hours on the stock battery, and anyone who isn't willing to wipe their phone completely.

This ROM isn't just a ROM, it is a system upgrade and every system upgrade requires a clean slate. You should treat this just like you treated the upgrade from Jellybean to Kit-Kat and wipe everything including internal storage. That is my advice, take it for what it is worth.

I am truly impressed with the work that Slayher, Fattire, and to everyone else who had their hands in making this a very strong build up to this point. You all should be proud of your work because this release of Cyanogenmod is quite good.