I had an iPhone 4 and when 4S came wanted a bigger screen so I went to Android with a Sensation XE(4.3") and then a Samsung S3 (4.8" screen). Like both although XE was a bit heavy/bulky in hand.
Since then bought more Apple stuff, iPads for kids, daughter got iPhone 4, and became more Apple'd. Waited until 5 came and was hoping for bigger screen than a 4" but still decided to buy as Android is great OS in some ways, but no way as smooth and slick as iOS. The home screen stutter/redraw was annoying on my S3, for a beast spec wise the OS must not be as well integrated as Apple and iOS is.
My biggest worry going from S3 to iPhone 5 was the screen size. I looked and looked and compared, holding side by side and thought I'd miss screen size loss too much. But you do get used to it. It is better to use in hand, S3 and XE was a 2 handed device, iPhone 5 can be used in one hand (handy for lots of applications, walking dog etc, sounds daft but true).
I would love a bigger screen, but I think in future Apple is going to have to have choice. As in a (lower price), "normal" one (as in now), and maybe a bigger screen. But then on other hand, with iPad mini I think they may not, 4" is 16:9 for media, and getting a 5" iPhone is too near to the iPad mini.
I'm glad I went back to an iPhone, the hardware is hands down the best, the iOS is lacking/limited in some ways, who knows what iOS7 will bring....