I did a clean restore on my 4S, restored my backup and then upgraded to 6.0. I've had it off most of the day to preserve my battery. Having poor Verizon service in my area sucks the battery life out of this thing so I'm saving the battery for work tonight. Can't wait to pay the ETF when it gets low enough to go back to AT&T.
Hopefully it's no worse than what I got under 5.1.1.
I won't be upgrading my 3GS on AT&T yet till the GM.