I take it that the blue clove polyps are (still) fairly rare. I picked up some a few months back with a shipment of aussie acans and until this post, they are the only ones I've seen or heard about. They do grow really fast, but because of their size I don't see them being much of a threat to other corals like some of the other fast growing softies and GSP. As rev said, they are miniscule. Because of that, I think you get a nice swathe of color from them, but I wouldn't say they really jump out at you. I'm just planning on using them as "filler life" for between my nicer specimens. Very cool.