I see tons of people saying that their battery life has suffered since upgrading to iOS 6, but I've actually seen a very drastic improvement. My office is located in a basement, where I have one bar of Sprint 1xrtt service (most likely roaming). This is the absolute lowest signal you can get before you have no service. I have wifi in the office, so at least non-cellular traffic like iMessages come through. Sometimes I even get a text if I'm lucky! My iPhone 4S spends all day searching for that elusive 3g signal, draining my battery steadily. If I don't touch my phone all day, it's usually around 55-60% battery life remaining. If I use my phone at all during the day, I'm lucky to end up with 30% remaining. Well I upgraded to iOS 6 a few days ago, and noticed that after moderate usage in my office, my battery was at 76% I tried to remember if at any point I had plugged my phone in to charge, but no, I hadn't. After a couple more days of usage, I can report that I'm seeing a very drastic improvement in battery life. I've been in the office 2 1/2 hours now (graveyards suck), and my battery is sitting at 97%. That's even after playing some music!