I'd agree 50/50 shot IME. I've had 2 over the last 6 years. Both in the same system,(46g bow front mixed reef)1st one lived 4 years, had a taste for Xenia/alveopora/ goniopora and the occasional pink/red palys with longer skirts, basically anything "frilly". My current one (just over two years) likes acans/micros/blastos & up until this point that seems to be it. Having said that I realize overnight he could decide to chew up everything including my crocea but I think their such awesome fish it's worth the risk, & I'm more of a zoa/softie guy so it works out for me! I also feed my reef pretty heavily and vary the diet. I would assume that helps a bit. Angels are "grazers" by nature and I think they often get blamed for coral deaths due to this nature. However they can still wreck your tank pretty quick so it's definitely a risk.