Of course the longer barrels on the original guns were for better performance with black powder. You get greatly reduced performance with the shorter barrels. The shorter barrel models were a concession to convenience. As far as accuracy goes, all things being equal, the shorter barrels have the same accuracy potential as the longer ones. As Lloyd pointed out, often the longer sight radius makes the gun easier to shoot accurately. In a handgun, my preference is a 4". It's all about balance and convenience to me.
Savage