They are nothing but trouble. They are constantly knocking over new frags, crawling in/on my corals, tearing into corals to steal their food, and killing snails for their shells. I am not replacing any of them when they die. I have one (Desmond) that is really cool and doesn't cause trouble but the rest I could do without. You can have an effecient CUC with just snails, stars, worms, and shrimp, none of which bother my corals.
RC, I want into your gang!