I have these, and I've got mixed feelings about them. They hurt for a few minutes after I put them on, and that's a turn-off. But once the pain fades, they actually feel kind of nice for a little while. The whole debate whenever I think to use them is, "Am I willing to put up with the pain this time?" I'm not hugely into nipple stimulation, though - I enjoy it, but I enjoy breast-rubbing more than nipple play, so these don't get a whole lot of use.