Aaron has a much better feel for the game than Marion ever did & he also has a better shot blocking instinct than Marion. On the other hand, Marion has a much better shooting touch & run the floor better than Aaron. Marion also was never a physical defender & didn't fared well against PFs. Although Matrix was a very good defender, he was never a lock-down defender.

Josh Smith is a better comparison b/c of his feel for the game, physicality, ability to be a lock-down defender & shot blocking instincts. Aaron can develop a broken jumper & decent handles ala Millsap.