I have been to this office 3 times - it is only two blocks from my work. The first two times I waited an hour. The third time, I called ahead to see if they were backed up. They said no and that I should come early as they could take me immediately. I walked over and waited 30 minutes (it would have been 15 if they had not taunted me).
That said, the staff and doctors seem to do a good job even if they are more expensive than local alternatives (maybe reconsider if you are on a budget without insurance).