As someone who has watched every single one of Colt McCoy's college games cept the one this past week (I <3 Cozumel), I have to say I don't think he's worthy of a top pick.
His completion percentage is huge, but he generally gets the ball in the right "area", doesn't hit receivers in stride, and when he doesn't complete a pass, he misses big time. With much faster and better DBs in the NFL, these passes are going to be picks. Texas generally runs a less complex offense as well, which took Colt a long time to pick up, I'm not sure of how fast he'll pick up an NFL offense. Finally, he's tiny. My roommate at UT that had classes with him said he looked like he had down's syndrome because of his stature.
That being said, he's a wonderful person, tough as all hell, and is a solid college QB. I just think he has a really, really long way to go to be an NFL-quality QB.
From what I've seen from Snead, during his time at UT, I don't have a lot of good things to say about him either.