I don't mean to play devils advocate because I'm going from an iPhone 4 to a SG Note 2 myself (sometime soon I hope) but the screen display quality of the GS3 is the reason I'm not getting it. The pentile screen uses a RGBG pixel color configuration that gives the whites a bluish tint, or green tint in some tests. IPS screens are more color accurate while the super AMOLED screens tend to over saturate colors badly. Outside of this, I'd pick an GS3 over an iPhone any day, but if screen display is of any importance, the newer IPS displays (nexus 4, HTC one X) smoke the GS3's display.
I do realize that the note 2 I'm getting does have a super AMOLED display, but it has been improved to a more natural RGB pixel display, mostly eliminating the bluish/greenish tint to the whites and gives better color accuracy, and size be damned if the screen has improved that much.