Except for GAIII's speed, I am a much bigger fan of Cam than I am GAIII. I think Cam showed more grit and smash mouth running style last year despite it being in garbage time and GAIII very rarely could hit the holes and was way too easy to bring down on 1st contact. I love it when he kicks in the afterburners and takes a 50 yard run to the house but I much prefer Cam's consistent 4-5 ypc he can get. If he can do that against tougher competition like scUM or Stanford, then I wouldn't have a problem with him being the #1 back. But it has not been proven just yet that he can. Then again, GAIII hasn't proven he can, either. I just hope between the 2 of them (or whoever emerges this spring and into the Fall) can come close to replicating what Cierre and Theo did last year.
I will add that one of the reasons I am so high on Cam is because during the Miami game (and maybe Navy, too), ND threw maybe 1-2 passes in the 2nd half and Cam got the majority of the carries and Miami's defense couldn't stop us. They knew we were going to run the ball and they still couldn't stop the run. That is pretty darn good for a 3rd string RB.