As a Tank, the only problem I've had with DPS has been them running forward and getting a lead on hate before I can catch up... Or worse, targeting a different group of enemies while I'm pulling, ending up nearly causing a wipe...

The big thing I've noticed with the DPS/Tank/Healer dynamic is that Healers and Tanks get most of the commendations; the healer is almost guaranteed a commendation from the tank, and vice-versa, because they heavily rely on each other. The DPS's are incredibly important for getting through the dungeon, but it's not often they get the recognition they deserve, in my experience.