just like Jerry Rice. Except at running back of course. I think Rice ran a 4.7 or 4.8 40 or something like that, and would probably suck at track, but on the football field, it was a totally different story. I think Dixon's speed is comparable in that sense, becuase like you said, he has enough speed to break off some big runs.
If I were him, I would maybe consider skipping the 40 yard dash at the combine.