IMO he had first round athleticism, but not first round size. If you look at his combine numbers, he ranked top for RBs in alot of categories. If you look purely at combine numbers (forgetting size) you might think he could be arguably the best back in the draft.
I'm not sure if he'll be able to be an every down back, although I wouldn't be surprised if he can be because I think he's more durable than your average "small" back. Even if he doesn't become an every down back, his return abilities IMO will give him a spot where he can shine for any number of teams.