So unless Nokia's original estimates were off (or AT&T did some more extensive testing), it looks like the AT&T version has less battery life than the global version. Granted it's not much but I just found it interesting, particularly because I was very impressed with 10 hour 3G talk time. Now it loses an hour talk time and 15 hours music playback time :(
I also noticed that the international version appears to cover all the same lte and gsm bands as the US version so it should work fine on AT&T here. I was hoping it would have changed to Bluetooth 4 since it passed certification but oh well.