Tiger cowrie

Well I have a tiger cowrie that has been in my tank for a long while, probably over 3-4years.  Anyway I have never really noticed anything unusual with it, and when I purchased it I thought it was reef safe.  Since I have been analyzing my setup, I did some research that indicates that they are really not as reef safe as I was lead to believe when I purchased him.  There are reports of them eating corals and sponges.  With some of the frags I purchased, I have seen him go over the top of them.  Never have I seen him directly eat any of the corals or sponges in my tank.  However, it seems like the ones he comes in direct contact with have a negative reaction for awhile after wards.

I love the look of him in the tank, but I worry a little that things could get worse with him.  I feel that he has been a major contributor to the cleanup crew, but I don't know if I can continue to trust him.

Also if I put him in my sump I worry that there is not enough stuff for him to graze on, but ???  I have a good amount of chaeto and patches of hair algae in it.  I guess he might be okay there.

Any thoughts or experiences with keeping one?

I'd trust him.  Then again I may be saying that because I'd rather have a cool cowrie in my tank than a cool coral.

Thanks for the feedback I appreciate it.  Well, I feel better about letting him back into the main tank.