Interestingly, I've had several friends and relatives say that they hate iOS 7. "Cartoony" is the most common comment and a couple people complained about having to relearn how to use the phone.
I haven't installed it yet, but I plan to. The appearance doesn't concern me much and the other advantages look attractive.
Change of any kind is hard. I just personally don't mind a couple of the quirks and in a way some stuff being new makes it fun.
Little things like swipe left vs right in Text (but now more options) and the close background apps...
having used both Android and iOS for a few years (Work vs Home) I was able to use them as reference for what the gestures might be that didn't work as I expected
I just feel like so far I like it more than I don't... and there's always folks that can complain no matter what... I like ATT.. some like Verizon.. etc. always something wrong with either
On my 4s is actually feels faster with the smoother simpler design
may not be true for others, but for me it is