I've read most of the responses here, and I haven't seen anyone say anything close to what happened to me.. so I'll post it here.
I got my 5 the other day, works great so far. Gave my 4S to a family member.. (by the way I never had any problems with my 4S with ios6)
Got the family member hooked up with my 4S, I thought everything was working fine until it went into sleep mode. Once in sleep mode it disconnects from wifi.. When I try and wake it up, it will not reconnect automatically. I have to go into settings and select the wifi.. It ***** butt.. Have no problem with my 5 and never had a problem with the 4S before. On that note though, I do have iCloud turned off.. and I know all settings are correct. it get's old to have to keep going in and selecting the wifi connection to use.
Any ideas as to what the heck is going on?
Thanks.