I have had 2 regals. Both yellow chested. My first was from TMC and "Red Sea". Arrived in good shape. Putatively QT'd and eating at TMC. Actually starting eating pretty quickly. I personally don't QT. I think that a healthy tank is a better place for a freaked out fish to acclimate than a QT. I know the arguements, but I just don't do it. Anyways, that fish died VERY mysteriously. Just found it on it's side without a mark on it in the tank. Didn't starve (frankly it was fat). Just Dead as a doornail. Just an FYI, this was a "too small" tank. A 55 gal FOWLR/easy reef (shrooms, polyps etc..)
Second one I got straight from one of the wholesalers in LA. It was apparently practically Just off the Jet. It also had a yellow chest, but was NOT red sea. Bali or something, I forget. This one was skittish in the begining. It was placed in a 180 gall reef, not particularly mature, but Tons 'o pods and "stuff" for them fish to graze on. I pretty much feed the tank macroalgaes, cyclopseeze and mysis. That's it. The Regal has never really been interested in the cyclopseeze. But it started eating the macro almost right away. After a couple of weeks it started on the mysis and has never looked back. This fish has been with me now for coming up on a year.
Of note I don't have anything to "freak out" the fish. My other fish ignored it. I've got plenty of rock. And uh, zoos....my regal is a zooanthid assasin. Otherwise, leaves corals alone and hasn't bothered clams either.