Those are cool critters... always enjoy feeding them when Frank has them in stock, though I am sure he gets tired of me rifling through the tanks to pick stars off the overflows to do it.
Not sure if you knew this or not, but you can buy large starfish like chocolate stars etc and freeze them, then feed the legs to them over time once they eat their way through the population in the tank. They are obligate feeders on starfish... or just put a linkia or sandsifter in the tank every so often for them.