He's explosive, his acceleration is top notch. He's very shifty, he has the ability to make guys miss with the best of them. He has "blazing" speed, and can beat most guys in a foot race. He's more than just a little faster, he's a hell of a lot faster than the other backs. In college he showed he had top notch vision, patience and balance. Those traits just don't disappear. He possibly just needs to adjust, and it's hard to adjust when you get no playing time. Obviously he isn't a power back, but neither is Chris Johnson or Jamaal Charles or Lesean McCoy. That's not a requirement for talent. He has the best hands of our running backs, natural pass catching hands. He's a terrific receiving back and knows how to do work and pick up yards in the passing game. He also is the most advanced pass protector not only on the team, but is pretty far along for the NFL. He has the instincts to pick up blitzes and shows the physicality and effort to stop linebackers in their tracks.
Just from what I've seen. Just because he hasn't shown these traits in the NFL doesn't mean they don't exist. His talent is insane. Nothing to do with his draft position.