I still think RAAMMAT is the best value for deadener. It seems right now the biggest drawback is Rick doesn't offer any kind of MLV. I ordered some of this stuff to check it out, it is super thick as I got the 1/4" stuff.
Aaron, what would you do with this if you had a roll of it laying around? Lay it on the floor?
http://www.usafoam.com/closedcellfoam/volara.html