I've had 4 and 5 then my iPhone got mowed when I was mowing then I got an iPhone again last September right after iOS 7 came out so I experienced iOS 6 for a few minutes before I updated and I must say I love iOS 7. I mean if you spend any time at all on your phone you should be able to adapt quickly.
iPhone really is the best phone going. Samsung tries too hard. I do like that curved lg phone. I saw a demo phone at the mall and I thought it was gorgeous and it was bendable and the paint repairs itself but I'm apple all the way