Apple Genius: "You shouldn't have installed iOS5 on your 3GS"

I upgraded my wife's iPhone 3GS to the latest iOS 5 software. Big mistake, the phones performance is significantly reduced and the camera quite often doesn't work at all. Given that was the thing my wife used most she was less than impressed. Not trusting me any more she took it to the Apple store where the Genius guy told her she shouldn't be running iOS 5 on her 3GS. Once she has backed it up they have offered to downgrade the software for her again so that it works.

You'd think iTunes would have a warning when it's advising that a software update is available that your phone's performance may be seriously impacted and some features may no longer work. I might have thought twice.

(Wife did think the Genius bar was excellent though and now wants a new iPhone)