This is my first smart phone and I am using it for past 1 year and I am quiet happy with it.
PROS- 1 Good battery life( how much I use it comes at least a day)
Excellent retina display.
Good sound quality an alternate for an ipod.
Best touch interface I have ever used.
Better build quality( no plastic feel)
Superb camera.
CONS- 1 No direct access to the inbuilt memory on connecting with PC.
Apart from that I am quiet happy with the iphone 4.