I have watched them sporadically this spring, but if I had to go with one over the other, I'd play Trevor Walls over Jeff Fleming at the Aggie quarterback position.
I have been impressed by Walls during practice. He's a big kid, but he has the physical tools and seems to be a more polished passer than Fleming. And, although not as athletic as Fleming, he's underrated in this category. I think he can move just enough and has a good enough feel for the game to stay off the ground enough, and give the Aggie offense a fighting chance.
The Aggies need to play the signal caller who they believe gives them the best chance to win. Forget everything else. The offense will have its growing pains, but steady play from the QB will go a long way. Poor play could sink the ship.
What do I think the Aggies are going to do? I wouldn't be surprised to see them go with a two QB attack. Again, they have to do what they think gives them the best chance to win. Whatever that course of action is at this point is yet to be seen.