on basketball reference, he comes out much better: http://www.basketball-reference.com/...l#advanced::19
you can see he has an impressive 98 defensive rating ("an estimate of points allowed per 100 possessions"), although he is bested by jefferson and adrien in that regard. he is also the second best defensive rebounder in the league (only beat out by KG) and the 7th best rebounder by percentage in the league for qualified players.
http://www.basketball-reference.com/...4_leaders.html scroll down to rebound percentage
i think it's most likely that he is not as bad as he shows up on 82 games and probably not as good as he appears on basketball ref.