Shaw's point is spot on. We're not that physical on Defense. That does not mean we cannot be good. Our quickness, smarts, a few top-tier players, and the experience of playing in the system together for a few years now, is our edge. I do think this D can back to top 10 status, maybe top 5?
One observation: It is interesting that Lotulelei is on the small side of an NFL nose tackles. Vernon Butler (6'3" 330) seems more suited for it. But I don't recall him getting a lot of time there, or doing much when he was there. I guess size isn't everything. Is Star's return is the the key to this Defense returning to elite status?
Some, I think. More important, though, is the continued development of ability, production, and leadership the younger guys: Edmunds, Oliver, Harrison, Epenesa, the rookie edge guys, Dane or Levi, etc.
If the D does (and I do think it will), combined with the Offensive potential, watch out!