Honestly - I'd go with who has had the most success as the QB and who will have the most success as QB for 2010.
Mallett? McElroy? Cobb? Garcia? - All those guys have had more success than Brantley.
Brantley was picked for the East, and Mallett was picked for the West. Can't really argue with Mallett. You could have picked him or McElroy and either would have been a good answer. But like I said, there just isn't anybody in the East. If Garcia could get his shit together, he would be a good QB. Cobb is a WR/QB Wildcat type guy. Hell of an athlete. Hartline is returning as their 3rd year starter at QB.
I don't know much about Brantley at all, but I'm interested to see what he can do. I mean, look at Texas' true freshman QB who came in and played like a man possessed in the second half of the NC game. Granted, our defense had backed down a little at that point, but that kid looked pretty good when he settled in.
Same thing could happen with Brantley. Maybe not. But it leads us back to the whole experience thing.