The LAT Int. sorbothane feet is just like any other component isolator products. It's main purpose is to isolate one from harmful vibrations. These feet are much softer than other brands' so be careful when installing them under heavy components since the sorbothane part could actually get mooshed out from the plastic base.
Sound performance: Used under both amp and CD transport, sound becomes much smoother and grain free. This is good but there are times when I wish the sound has more edge to it. Of course, it all depends on the components used. If you need to get rid of some grain then this should be a good tweak to try. For the price, it is probably the cheapest in the market.