Brown Electronic Labs (also known as BEL...to the extent it's known) has some hard rubber feet that are also sold separately that are supposed to be better than the usual feet.
This is my experience: I tried Symposium stands. Using their metal "feet" (that you place between your gear and the stand), I found that the sound seemed hard and bright. I then tried the BEL feet. Liked the result a lot better.
I also tried some kind of wood "feet" from Cardas. My ears heard the same thing. Hard support, hard sound. Maybe it's just psychological...but I've heard others say the same.
There's a good discussion of various of the vibration-damping systems at the Galen Carol Audio website (gcaudio.com).
The BEL feet are very inexpensive...I got mine from Audio Concepts Houston, or I would assume you can get them from BEL.
Just my 2 cents - I think vibration control has some importance, but I think there's a lot of "voodoo" hype about it out there. I'd ignore the literature and listen to your ears (while hanging on to your wallet!)