After extensive testing over the past month or so, of all the roms available for the Mi2, I have to say I'm most pleased with WIUI 3.2.22. The Experimental version did manage to put my device into Deep Sleep much more often, but I can't say I noticed any real perceptible improvement in battery life, if any. I did, however, notice that some apps were not functioning properly due to the JLB7.0 kernel, most notably, Netflix (audio was going out of sync).
I had been flashing all the WIUI versions on top of each other without wiping and 3.2.22 was the most stable and appealing to me (I don't like the look of MIUI v5 aka WIUI 3.3.x). I've since done a complete wipe and flash of 3.2.22 and it's running smoother than ever with respectable battery life and everything is behaving as it should.
Overall, the Mi2 in combination with WIUI has been the best experience I've had in a LONG time--since the HTC Desire. I've tried flagship after flagship from HTC, Sony, Samsung, LG, etc., and no phone has been able to check off as many items as the Mi2 + WIUI.
The only glaring defect left right now is the microphone volume. It hasn't mattered what rom I use, the volume is incredible low, so low that I can't even use speakerphone because people on the other end can't hear me. Similarly, if I use an audio recorder, I have to have the phone right in front of my face and speak loudly in order to get any decent sound. Finally, with Google Now, I used to be able to speak casually with other phones and get accurate results, but with the Mi2, it's like I'm using an iPhone, that is, it gets everything wrong. In each of these scenarios, it's the microphone that's the issue so I don't know if there's a way to boost its sensitivity. I don't know if it's just me because no one else seems to be complaining about it. Otherwise, this phone is simply the best on the market right now.
