As a starting PF, he's probably the 20-30th best in the league, which is considerably below average. As a first PF off the bench, he'd be a top 5 in the league.
As some have indicated, he'd be a great piece for a contender to acquire.
I think his role will be bigger than expected because we have 0 centers and he will have to play some or the other PFs on our team will have to play some. We have a "logjam" at PF on this roster, but that logjam is going to be spread over 2 positions so I think they'll all get more minutes than expected.