Dante's sound deadener carpet

I see that Dante's has some pre-cut peices of sound deadener. Has anyone ever used this product?
I know that there are many ways to insulate the floor before putting in the carpet,Fat-Mat, Dyna-mat ect. But this looks pretty nice with the pre-cut sections. It could make the job very easy.
Here is a link to it. http://dantesparts.com/sounddeadener.html

Thanks..............Ted