Hey Nick. No, had never heard of it. (means nothing). It looks a bit less expensive than Dynamat Extreme, which seems the insulation of choice here. I just recently went on a quest for sound proofing for my front floors -- but could not justify the expense of Dynamat. Maybe after I redo my floor panels but not just yet. I then found some stuff at my local NAPA autoparts store. It came in a roll 4' x 8'. Silver foiled on one side and about 7/16ths thick. Unlike Dyno, however it is not self-adhesive. A little 3m spray solves that. 24 dollars.
Just this morning, on a brisk top-downer to work, I think it makes a sound difference. Hear the pipes from the back instead of underneath...
James
63 230SL