Out of these 4 there are a lot of concerns all around in my opinion with these guys as NFL backs. That being said I think Rice is the most NFL ready, but he may never be a feature back. Johnson doesn't impress me much, Boise is just a nice story. Slaton still has to do a lot more to prove to me he is nothing more than a system back. And McFadden again with the system, but he is also runs way too straight up for my taste. McFadden definately has the most potential of them though.