[I've heard that the Copperband will not completely eat the aiptasia from the rock, leaving enough of it to come back. Also, once the aiptasia is gone, you will have to get rid of the Copperband cause it will feast on your corals.
I had about 30 Aiptasia in my tank, a real bad break out. I picked up 3 Peppermints and they cleaned almost every one up in about a week and a half. There are only two left, a very large one which I guess was the initial specimen and another small one that they have missed for some reason.
You can get Peppermint for about $6-7 at most LFS's, or $85 at Dallas North :laugh: .
Good luck]