I noticed a pretty significant reduction in battery life since I bought the device. I see people getting 5-7 hours of screen-on time; 4-5 days idle time, etc... I could easily do that when I first got it but after around 2 months, I'm lucky to have 2 hours screen on; I'll drop about 10% over an 8 hour period on idle... I've tried on fresh installs of both TW and AOSP; adding none of my own apps and the results are the same. Stock kernel, Ktoonsez kernel, various settings, etc... I've also noticed that sometimes, say the status bar will tell me I've got 92% battery left; I boot into recovery and TWRP tells me I've got 97% left. That, to me, sounds like the battery is going south so I'll be trying a new battery here soon.
Don't be afraid of the "Thanks" button