Mapleshade HeavyHats-Do they work?

Does anyone have any experience with Mapleshade Heavy Hats? I am thinking of using them on my Cary 303 cd player and/or my Rogue 99 preamp. I am currently using BDR cones under both components. I know they are pretty cheap but I can't see throwing away any money on something that doesn't work. Thanks.
I think the theory that placing some weight on a large metal case does effect it's vibrations/sound is pretty widely accepted. There are many items that can be used, I have several sets of brass Heavy Hats as well as several sets of brass Heavy Foot cones that I use. You have a trail period with Mapleshade, and the price is very cheap, like any tweak you have to try it in your own system. It will not be real dramatic change, just subtle improvement in my case, brass does seem to have very favorable effects on sound vs other metals. Even if you don't use them worth having to experiment with.

They also look much better vs bag of lead shot or other DIY items commonly used.
I think that would most likely work. I noticed on my Cary CD303 that while the thing is substatially built, the top cover rings like a bell. My solution was to line the top cover with some self adhesive dynamat. Its used in car audio applications but works wonders on damping metal cases too.
Audio Research make some that are very afordable that work well for me in my amp and preamp. They fit 6922 size signal utbes.I use the "clear" dampers which require 2 per tube. Still only $8 a tube.