After upgrading I have noticed more battery drain, even with almost everything that can be turned off, turned off.
If you look at the usage time, it increases even if you have your phone in standby. This is normal if the amount of usage can account for the stuff you have activated, like fetch mail or whatever. But I have been watching this meter and 30% of real standby time drops on the usage time, so it gives me the sensation that the phone is doing more stuff on background than expected. And it heats up on standby too.
As reference, with the previous firmware and same settings, 10% of real standby time accounted for usage time. So, for me, something has surely got worse. It's pitty because its now under the 24 hour that I consider minimum for mobile battery life
EDIT: i missed the subject, my ophone is 3G, not 3GS