I was having battery draining problems with my stock MK2 4.3 rooted. I had seen several forums with users complaining about the same thing. Long story short, I had messed up my phone trying to mod it and had to Odin a stock ROM. I Odin'd stock MJA, OTA updated to MK2 and re-rooted. The unexpected benefit to this was I how have outstanding battery life. I have absolutely no idea why this helped, but I figured I would share it so that it might help others.