I finally clued in to the "Sally Jo" reference....
I have starfish that look like the ones vilified on GARF, but they have never posed a problem for me.
I remember many many years ago, a discussion about these stars on rec.aquaria.marine.reefs, Mike Noren was saying there were species that were coral predators and some that aren't. I beleive Delbeek and Sprung say the same thing somewhere in their TRA books: some OK, some not.
The ones that I have, because they divide by fission, are almost always in some state where half the star is regrowing and thus lob-sided.
I have them in all my tanks. Never seen one on a coral. They seem to do a pretty good job of keeping the glass "reasonably" clean... (for certain they do a better job than I do..
ops: )