I have never owned any Harlequin shrimp, however I do find them very pretty. Now having said that I'd just like to add my comments. As much as some of you think it is cruel to feed them the starfish, it IS the natural thing for them, like it or not. Whether it happens in your tank or in the wild, it WILL happen. What about raising rotifers, or what about all the little buggies in the refugiums for the fish to feed on? They are also in a closed system with no where to escape to, and eventually every last one WILL be caught and eaten by one fish or another. I would also like to have them in my tank, unfortunately where I live stars are too expensive to use as food.
Now having also said that, I'd like to say what I DO know about them. They can live in a community reef setup as long as there is notheing else in there that will go after them. A tank with all peaceful, docile fish is good. Linkia type stars are the proper type to feed them, as this is what they go after in the wild. Other types such as the chocolatechip types are not. Also, the chocolatechips are not reef safe anyways, as they will eat lots of the corals ( there, how about that, isn't THAT cruel if a star eats a coral, afterall, corals are live animals also, right???). They also tend to do better in pairs.