You're lucky, on my Iphone 4S it's a disaster. Everything is slow and has sometimes nearly a one second delay, Safari, the camera and a lot of my apps keep crashing, mail doesn't fetch emails automatically and most of the times even not manually, there's still a bigger battery drain than IOS6, browsing the internet is very slow with safari, etc.On my 5 it's really not very buggy and I don't think I could go back to 6.
I wonder how it's possible it's so different from one phone to another.