My 34 gallon has a dwarf lion in it, along with a coris wrasse, scopas tang, and a mandarin dragonet. At one point I also had a stonefish in there, one of the semi-lethal varieties. Just can't keep tiny little stuff in there, but he doesn't mess with anything that's 3/4 of his size or larger. He takes down silversides, but they need be torn in half, and at that I've gone for periods feeding him only mysis shrimp or comparable sized foods, and he was unable to take down any large food until he had been weaned back up to that size.
As far as having him in a reef tank making it interesting to work on the tank....this is true. I've yet to get stung by him in over a year of having him, but he is incredibly friendly and tends to sit right where I'm about to work. He's used to my hands in the tank though, and doesn't get ornery, so I'm usually able to shoo him around with my hands. It gets annoying sometimes though as he is used to eating out of the tongs, so anytime he sees something shiny he chases after it. Makes fragging with clipps very interesting.