Coming from a non-gun nut (but one that shoots occassionally)...
When I first shot the Sig, I didn't like the trigger pull for my hands. It was too long. Then I got the feel for it, and it's very nice. I've put several hundred rounds through one during deployment quals or when we needed to blast through our fiscal year ammo. Nice gun.
I had the chance to shoot a Barretta once or twice, and after having shot the Sig, I did not like it. Seemed more sloppy and like Bubba is saying, harder to maintain a sight pic, for me anyway.