Keep IMO
I've had one over a year with no probs. Except that recently it got into a fight with a pistol shrimp and had to be moved to the sump to recover. I'm hoping it is on the mend, so difficult to tell though. The damaged areas don't look white though and seem to be growing back.
They are great detritivores, so if you have a big tank they will browse on the live rock.
I feed mine from time to time with defrosted krill, which it takes greedily. It also likes fish pellet food. "Smelly" stuff excites it most. It doesn't seem to like mussel though. It runs away! LOL