Arthur,
Here's a link to a set of the style I am using from Ebay:

http://cgi.ebay.com/Bowtech-VibraBlock-anti-vibration-system_W0QQitemZ7209069117QQcategoryZ36100QQssPage NameZWDVWQQrdZ1QQcmdZViewItem

I have no clue if they are affecting performance but they do work. They're pretty light but I don't have the knowledge to know how they would affect limb action.......all I know at this point is me add rubber make bow quiet.
How much performance do the heavier cat whiskers eat up vs the beaver balls?
The Pearson I have shoots great but I would classify it as noisy compared to the Bear and Shakespeare.
I'll see if I can find another set laying around and if I do I'll send them to you to play with.

(On an unrelated note: I have to say too that it's funny for a guy like me to be gravitating toward the pokiest bow of the 3 as well)