I've been totally unplugged from the outside world for the past several days. No WiFi, cell coverage, etc -- absolutely nothing. Knowing that ICS was about to be rolled out to the masses as I was leaving, I was really looking forward to updating my phone when I got home. Had I known what it would do to my phone, I wish I never would've returned.
I installed ICS on two devices last night -- both with nearly a full charge before downloading. My wife's Razr had approx 50% battery when we went to bed -- it completely died overnight. Although my Maxx didn't die, it's been draining much much faster than normal.
We had exceptional battery performance on GB. Now it downright sucks. I haven't had the time to go through all of the posts and possible solutions since I've been back, so I know I've got some reading to do. I don't know if it takes a while for the phone to "settle down" or what, but at this point I can say I'm not thrilled at all.