In theory, the greater the radius, the greater the human potential for precision of alignment. I don't think however that you'll see an inch reduction in group size at 50 yds, with the addition of an inch of sight radius.
How are your eyes? Will an inch bring the sights into better focus for you? Will the inch increase the gap between blade and notch, or will that be compensated for?
(Wouldn't that be great though... with a long enough barrel, you could shoot in the zeros. )
An inch of barrel and slide will have an effect on muzzle flip and X time reduction in the return to target.
An increase in muzzle velocity too... but nothing earth shattering.