I don't know about everyone else, but all of my iOS 6 devices suck with Wifi (iphone 4s, ipad 4 and ipad 2)
Starbucks Wifi won't work - the splash screen that you need to click 'i agree' on often wont pop up. I'd have to turn the device off and on.
Wifi hotspot plain stopped working. works fine on iOS 5. Rogers Canada here...
Add to that I'm getting around 1 hour less battery with iOS 6 (on iOS 5, i'm going home with 80-85% battery life.)
now I'm lucky to be in the 70s
pain in the butt over all. hopefull