Product review (4 stars): Awesome but expensive
First let me tell you my situation.  I put our frontload washer and dryer on pedestals on our second floor room in a converted closet/laundry room.  It's in an old house with a floor that slopes, I leveled the washer with a bubble level and could not get it to stop shaking.  It shook so violently that it would walk across the floor.  So I ended up taking lag screws and screwing it down to the wood floor.  That is how it was for about 10 months.  It would shake most of our upstairs including our bed pretty bad.  Then I had to have a maintenance call for a broken door latch and he said it was bad that I bolted it to the floor cause there was no place to dissapate the vibrations and was hard on the machine.  He suggested a rubber mat.  Well I found these, saw the reviews and bought them.  I was so skeptical of it working once I started unscrewing my machine from the floor.  The memories came back and I thought there was no way it would work.  Well I installed them and I am absolutely amazed.  The washer doesn't walk at all.  If I stand more than 3 feet from the washer, I can't even feel vibrations on the floor.  If it worked that good for me, I can't imagine the results other people are getting.  I am very happy with the product.  The only drawback is the price.  I had to buy two sets to make the dryer the same level off the floor.  The dryer doesn't need it but what else are you gonna do?