I've been getting amazing battery life on iOS 5.1.1 and generally since I purchased the 4S. All updates were OTA. I get around 8 hours of heavy usage with 2 - 2.5 days of standby. Heavy usage means 3-4 hours gaming like zenonia and monsters ate my condo, messages, a couple of long calls, web surfing. I love how I never need to toggle my wifi or GPS. They are always on, as with all push notifications from twitter, facebook etc. Coming from a bad experience with an android phone where I used to worry about turning everything off and even then I'd get 12 hours of total battery life in standby. In standby mode with not much going on it can go for atleast 4-5 days. Here are some pictures, with heavy use and on standby where my battery dropped only 2% in 11 hours this is with everything including wifi connected. And if anyone is curious I owned a motorola XT720 before this.