I had a small (3") scribbled in my 120 mostly SPS reef for about a month. Got it from DD. Gorgeous fish that got along with all of my other fish and ate everything I threw at her. However, once she settled in, she became the "mouthiest" of all my fish -- including my slightly smaller Regal -- picking at every coral and clam in the tank. The tank is in my office so it is easy to feed 5-6 times a day, but that was not enough to keep her off the corals. I decided I valued PE on my stoneys and exposed mantles on my clams more than her and re-homed her. She is now quite happy in a FOWLR. My conclusion: like all angels, they are reef safe "with caution". I got lucky with my Regal, but unlucky with my Scribbled.