I did an over the air update today on the 4S and the battery life was very good. It was 60% 12hrs laters after light usage. However, I was facetiming tonight with an iphone that didn't have the new update, and after 3-5 minutes, the phone auto-rebooted itself. I thought it was a one-off but it rebooted itself four more times. Sometimes the reboot happened as fast as 5 seconds after connecting to facetime. I ended up just talking over the phone. Has anyone else experienced this?