I think they work good. u have to use a string splitter to put them in but other than that they are pretty good. i used them on my hoyt and they helped. there is no point in having them on my general b/c it is so quiet and vibration free already.
btw, it helps to have them served in b/c if your bow isnt tuned well they can fly out. had that happen a time or two on my hoyt when my string started getting worn out.