I don't have iCloud back up turned on. I have kept all my settings the same as they were under 4.3.5:
wifi on
BT on
push on
brightness 50%
no problems
Now, drain
I charged to 100% and took it off the charger at 8.10AM EST. It's not being used, and is cool to the touch...I will check it at 9.10 AM EST, one hour later. If there is significant drain, I will charge to 100% and turn off wifi and BT and do another one hour test. If the drain is gone, I will try bringing back BT only, and do another check. Hoping I can isolate it to BT or wifi....but my wife's iPhone 4 seems fine, as does my iPad, both iOS 5.