Functionally, iOS 7 is far superior to iOS 6. But I can see why someone may not like the visual design. Personally, it doesn't bother me, and some of the visuals have even been improved (good riddance, sucky skeuomorphics).
All in all, I'm very happy to have updated even though I hate the new Safari icon.
I do rather dislike the white look, wish I could turn on a darker theme. And I really wishy I could turn off those stupid long transition animations. Aside from a coat of paint I don't like, all I'm really seeing is easier access to some system controls and better notifications on an os that runs slower on my device. if it wasnt for board/card games I'd be considering a switch to a nexus tablet to match my phone.