You are talking about the NV system by PSE but made by Simms. I have them on my mighty might. They work pretty well on it. I don't know that you would need them on a Mathews though. They cost like 50 bucks or so when I got them, and you have to take the limb bolts out to install them (shop if you don't have press).

I also have the stick on limb savers. I don't believe you can have too many antivibration devices on your bow. Vibration is the enemy! I would install string silencers as well, even if you don't notice a difference. I have never heard a bow that didn't benefit from them. Even the ones that have them built in, like the mathews and the such.

Paul