I have had my two for almost three years...read smokin urchin post. I havent had any problems with them at all, however, mine are pin cushion and not long spined. I wasnt getting any coraline growth and was ready to get rid of them. I was told that they actually will help with corraline growth due to their messy eating habits. because they are so messy they help to spread the corraline around the reef. In the lasy month, I have had a huge growth in corraline algae and they dont seem to bother it at all. I think if you polled everyone(which I did on another BB awhile back) that there would be a huge split. I personally dont plan on getting rid of mine.