12 hours of low usage on silent/wifi/3G, 4 texts and 9 iMessage, 2 emails sent, no browser activity or camera etc due to being busy now on 35% battery, before update I was usually aroung 60+% easily.
At one point, my iMessages stored in conversation wiped off to only the first and last, then restored shortly after.
Tempted to use my Applecare as its unusable if it cant survive a working day where it's hardly used. iPhone 4, bought on launch day so the battery could be on it's last legs, on nearly every charge the battery is calibrated (turned off due to drain then fully charged).