I have mixed emotions about the use of this fish in the hobby.
I've got one that's done very well, but most do not. The key is to get one that looks fat and is eating. They tend to be very shy at first and some just waste away.
Once they're acclimated and eating, they're easy, but can be obnoxious like any angel.
Mine eats anything I put in. I feed it a mix of frozen foods, including mysis, squid, shrimp, clam, scallop, cyclopeeze, nutramar ova, angel formula, and nori soaked in vitamins. I also feed New Life Spectrum and Formula Two pellets.
They are known to eat soft corals. Mine is in a tank filled with softies and, except for a few nips on some anthelia, he's never bothered anything.