Exactly. Both had team speed, Auburn's were just much bigger, and it wore on Oregon.
The other difference, IMO, is defense. Period. You see teams like Ohio St., TX, OU, and Oregon the last three years that averaged 40 or more a game. In BCS title games against SEC teams they scored 19, 24, 14, and 21. Most of them scored half of their yearly averages, and in all but last night's game all had a garbage time TD.
The fact is they don't see the size and speed of SEC teams regularly, and you simply can't practice for it. It's a different animal, and it always shows in bowl games. I personally think it is the only reason ACC teams show well against SEC teams in bowl games. In most cases, they have enough similar athletes to compete.