The one I've personally seen do well long term (5 years+) was in a 150 gallon FOWLR tank I was taking care of for a coworker, and it was an old and dirty tank. (Mulm like you wouldn't believe.) From what I've heard since then, they like low maintenance / higher nutrient tanks (not in the uber clean carbon dosed sps systems) with mellow tank mates who will leave them in peace and at least 100 gallons with no other sand sifting critters. Most of them I've heard of will eat some prepared food as well, but they seem to do better with plenty of sufficiently dirty sand to snack on.
I also think this is one of those species that suffers badly in the collection to LFS transition. Because of their picky eating I think they tend to go a couple weeks with suboptimal nutrition in what is already a stressful situation. Most of them I've seen in my LFSs are kinda thin and apathetic looking. Not sick perhaps, but I think by the time they get to our tanks they don't have too many reserves to keep them running while they acclimate to captive diets.