I assumed that the decline in rebounding rate for Sullinger is attributable to his rehab and present level of conditioning. It's fair to point out that Love's rookie year rebounding rate was decidedly superior to Sullinger's, but it's definitely fair to say that they were both elite in that respect. I ought not have implied that Sullinger is Love's equal as a rebounder.
Very good, yes. Elite, no.
It's fairly straightforward to identify who the elite rebounders were last year: guys who pulled 25-30% of the available defensive rebounds, and ~20% of rebounds overall. It's a pretty short list:
Evans, Vareajo, Asik, Drummond, Hickson, Vucevic, Randolph, Duncan, Howard, Chandler.
Cousins, Okafor, and Sanders are on the bubble.
Sullinger is in the tier below these guys.