I've seen both Luigis and Wood, and I'm not very impressed. Wood is VERY light at the position, regardless of what his weight says. If he's getting consistently bull rushed in college, Wilfork, Jenkins and Ferguson are going to have their way with him.
I'll probably post this a hundred times from now until the draft, but what I believe the Bills need in a center is a very strong, stout player who will be able to stand up to the large 3-4 DT's over his face for half the year. It does us no good to draft the smart-smallish center, we already have that in Fowler. I believe we need a smaller in height, larger in weight-type center, who is very good in the run game, and that is EXACTLY what I see when I watch Caldwell.
Mack might be the best overall center, but for the Bills needs, Caldwell fits the bill better. Again, I will end up posting this a hundred times from now until draft day, because most fans just look at the "expert rankings" for centers, see some guy named Mack at the top, and vow that's who we must draft and that he's the best.