Winston was a fantastic college QB, but he wasn't as dominant as Vince.
See, the thing some of you are missing is how Vince looked like he was playing a different game than some of his opponents. There he was against USC, a team with NFL talent all over the place and one of the all time great college teams, and he clearly looked like a man amongst boys.
Winston never looked dominating like that over his opponents. As Skid said, it isn't just the stats (which are impressive in their own right), but also the way he seemed to take over a game whenever he felt like it. And sometimes you just need to go off the plain old eye test. Vince just looked the part.