So like most S2 owners that have come across this post, I'm hoping that I am at the end of the journey (at least for now) to find a ROM that gives me good battery life on my S2 GT-I9100.
PROPS to the original poster for starting this thread. Read it several times, and here's my journey:
Problems began with the last JDI update I9100WBMS3, and the one just prior to that. Always used stock ROM. In addition to wanting a fresh interface, the battery woes were killing me primarily, and performance started to suck a bit after installing a few games.
Here is my experience with some of the better known ROMS, in order of what I started with first - Always did full wipe, install ROM, SU where necessary and GApps:
1st - HAZY. (Lollipop)
The Good: Beautiful and clean. Stable. No app crashes. Nice Lolipop experience and flavor.
The Bad: Battery drains from 100% - 0% in like 6 hrs (1.5 hrs talk time, no games, no browsing)
2nd - Euphoria. (Lollipop)
Same as Hazy, few more customization. Battery life sux
3rd - BeanStalk (Lollipop)
Almost same as experience Hazy and Eupho. Battery life sux
4th - NeatROM 6.4 + NeatROM Kernel
Didn't get a good chance to see Battery life, but after full charge, BUT I could see that the battery life was going to be better. Not wanting to be stuck with 4.1.2, and with my ROM flashing addiction on full overdrive, and I couldn't resist doing another ROM a few hrs later. Which leads me to my current ROM in use.
5th and CURRENT:
CM 10.1.3 stable + Dorimanx-V9.43 Kernel.
The 4.2.2 flavor is not bad, definitely better than the old stock one in NeatROM. Battery life appears to be good based on posts i've seen here, and my past experience when I just got the phone.
See images attached for battery use.