I think 'elite' is probably thrown around too much these days. Very few should be worthy of that status. Ladainian Tomlinson was, I believe Ricky was.
Adrian Peterson IS. Could up end up the best of all time if people are ready to move on from Walter/Barry one day.
But who else right now could make the claim of elite? Surely not two rookies or Stevan Ridley lol. Doug Martin has a lot of potential though
Names I'd throw out there I guess... Arian Foster, MJD, Rice, Jamaal Charles, SJax, Marshawn Lynch. But I don't know if any of them belong in the elite tier with Peterson. Surely all upper-echelon though