I don't like PER b/c it is so skewed to offensive productivity, but many do... and for those that do, Sully is at #22 right now, ahead of Wall, Marc Gasol, Pau, Melo, Rose, Bosh, Zbo, Kobe, Howard (not exactly guys you'd expect to be high on PER, but all-stars nonetheless).
Second point, how do we know Sully isn't playing 36 mins due to conditioning/weight issues? Is there any data/information to suggest that? Seems to be no more credibility to that argument compared to the argument that we have a logjam at his position, and want to display players for trade purposes.