I will say that I don't think McGuffie is as good an NFL RB prospect as Hillis, Woodhead, Gehart, Beaver, Burkhead or probably not even Nile Knapp, John Howell, or Eric Gerber (if they end up getting PT in college and add a little more muscle). McGuffie is built to be a scatback, but sometimes stuttersteps too much and doesn't show good instincts often enough. McGuffie might wind up like a Reggie Bush in the NFL, (but then again Bush isn't a bad player, he's just more of a third down back specialist). Of course Bush returns kicks too which Guff doesn't do yet.
Not comparing styles just how much of an impact Sam would have: I'd say McGuffie is about as good an NFL prospect as Wegher, Line or Sharp. I'd say. Two guys I watched a lot at Rutgers that Sam is a better runner than are Martinek and Leonard, Guff is also better than Nate Kmic, Stan Zwiggi, Blake Smolen or Michael Campanaro as a RB. McGuffie is a FAR BETTER propect than average college back Luke Lippincott lol.
Guff started to come along more towards the end of last year. Once he makes the first guys miss, he needs to use his burst, speed and balance to his advantage while hitting the seam and breaking arm tackles while heading "north-south". He also seems to try to juke too late in tight space at times- to where the defense can completely collapse on him. He needs to make his cut a little earlier and use his "crazy legs" to leave the defender(s) in the dust.