I have used several of them and they do work very well, some are better then others. So far the best I have found was the Jtec anti vibe but unless you are building the plane, mounting can be a slight problem due to how you have to counter sink the mounts into the fire wall. I mounted one on one of the CG Extras with a YS 1.40 and was in shock at how well it worked, zero vibration. I knew I was going to used one so I made the fire wall from thicker ply in advance. Hyde has a new one out that doesn't cost an arm and a leg. I haven't tried one though so don't know how well it works. There are a lot of good ones out there right now.