Yeah, have to admit as much as I liked the iPhone 5 feel (especially when outside a case), every stretch of the thumb or wrap around of my pinky, to push some corner button opposite my palm makes me miss the 3.5" screens. Go big with two hands or stay with one. I have long fingers and 4" screen feels in between.
EDIT: Or I guess the coders could place the interactive components within a reach range and the full-screen would be there for the eyez.