I too dutifully updated to OS6 on an IPhone 4 even though it was working great on OS5. (Next time I’ll check the blogs first) However, I found the problem with my configuration… and no it was not OS6. And since this is my wife’s phone, I was VERY motivated to find the problem!
I’ll spare you to days of resets and reloads from every cloud and computer available to me. I finally did a hard reset with just the phone and finished the setup with just the phone and no cloud, no iTunes. The phone seemed stable and battery life was normal (normal for me it two to three days if I dial back all the data chit chat). Then one at a time started adding back apps. When I reconnected my exchange email account (Hotmail), the battery drain kicked in (3 hrs to dead). After reading about some of the “push” issues, I switched from “push” to “fetch” in the email settings and the phone only dropped 2% overnight! Yea!!!
We all have different apps interacting on our phones (had the same issue with an android phone). Apple has always been brilliant at stable software but they cannot foresee every app interaction or predict how servers with interact with our apps. I’m not a big blog writer, but I’d suggest folks try what worked for me. Start with a truly clean install and add one app at a time. I’d also suggest apps that sync and exchange data (email, calendar, social apps, etc.) frequently would be the most suspect.