i was anti iphone for years even though my wife had one since they first came out - switched from blackberry... after years of getting phones that were kinda like the iphone but not, i finally got one - this was iphone 3g... after trying several other phones i kept coming back to the iphone for it's intuitiveness, ease of operation, the apps, and the fact that it now has my music so i don't need to carry my ipod and a phone.
i live on the phone and do everything from phone, email, games, music and i carry it it my pocket... not a holster kinda guy... so the size only makes it better... i probably do 10-15G of data/ month... the guy at the store didn't believe me, either... i'm grandfathered in on the unlimited plan and by god i'm stayin'...
i have the 4s now and while i'm eligible for the 5, i have no reason to get it... gonna give it a few months and see how they do... but i can't see why i'd ever change from the iphone... personally, i'm rough on phones and i drop it daily... usually in a parking lot or my driveway... i've had the 4s since they first came out and so far i've not had any issues with it...
aside from that, i run pc and mac for work and the mac compatibility with the iphones is fantastic... cloud storage, picture moving from device to device...
and plain and simple... it just works...
i'm an AT&T user for over 10 years and they treat me like a king... probably because i have a half a dozen cell phones for personal and business and that's not cheap...