DESPITE his height & mobility suggesting otherwise.
Defensively, I'm pretty sure I'd take Mag as a PF or as a SF over Waterman in every matchup we saw in the Big 12 last season (but probably not on guys like Dickinson or Burns — two matchups that Noah is remembered particularly fondly for). And Waterman was arguably our most versatile defender last season. Guarding athletic wings & PFs was NOT his strength, though — but particularly PFs. In a lot of those matchups he was just okay — at best — & in more than a few he wasn't even that. While Noah's shooting is clearly better than Mag's, when you factor Mag's slashing together with his transition game, I think the two are far more offensively comparable than a lot of posters on here have feared or stressed.
And that's leaving Demin & Catchings(yes please!) entirely outa the conversation.
As for Atiki — the gap between he & Keba is quite a bit more severe than the gap between Mag & Waterman. On either defense or offense. Keba not only IS significantly stronger (particularly in the core & legs) — he also PLAYS much stronger. He keeps his legs under him much better than Atiki.