Shit screen? Lol, now I know you're joking. The display on the 4 is amazing. My old 3GS' battery life was better than the sensation too.

Size is obviously personal preference, but suffice to say there's a perfect size for a phone with a 100% touch screen. After using the s2 it felt too big for me, if bigger is better then I guess you can only hope the s3 is the size of an ipad