They're OK, and seem to stay in place whereas Head damper comes out a lot.
It makes my game more comfortable
Makes my Wilson Racquets look good!
Personally I'm not keen on dampeners, as I like the clean feel of a true shot, but they keep telling me these things are better for the arm. So's a banana. But okay, if you use them, at least use these, in my experience they don't come off no matter how hard you hit and they must be discreet as you quickly forget the difference that you feel at first.
Perfect amount of dampening.