I think he said Center. That would exclude guys like Davis. I would take Demarcus over him (he's also the best center in the NBA right now). But no other centers really come to mind.
I think he also meant it to mean good when they first came in as freshmen. No doubt guys like Noah were better players but it took him a couple years to get there. Okafor has been good offensively for Duke.
Cousins is the best center in the last 10 years and maybe 20. I always thought of Okafor as DeMarcus but just not quite as good. DMC put up 16 & 10 with a loaded backcourt and frontcourt. Okafor is a one man show down low.