To Kill or not To Kill, that is the question...
I picked up my Evo last Wednesday and have been trying to identify if ATK is needed or not since then. My first couple of days were spent scrambling for power outlets, always trying to keep the phone on a charge, it seemed to eat batteries like a fat man eats chips...
I found a few guides on battery life, applied a slurry of changes, installed ATK, and the battery life definitely got better. I would watch ATK and it would find large lists of apps that I didn't want running, and I'd kill them each time I locked the screen...
Yesterday I read through 14 of the 16 pages of this thread, and after seeing the process life cycle, and getting a better understanding of how the Droid works I disabled ATK around noon yesterday. My battery life didn't change over my afternoons use, and thus far today it's been behaving it's self as well.
All said and done I run about an 16-18 hour day with two 30-45 minute commutes that I charge during. While commuting I run Pandora + Bluetooth + Navigator (not that I don't know my way home, but it's the "oh shiney" factor

) so I don't see much charge gained in this time. When I hit the rack I still have 30% battery left, which is more than enough to keep me happy.