I use treo mat and dynamat extreme, performance is the main reason for me. I plan on using second skin to give it a try since is from what I hear better then dynamat and cheaper, so I will see. I have used hush mat and prefer dynamat extreme over hushmat, the dynamat was alot heavier, I really like treo mat, it is like two layers of dynamat extreme, just a pain to work with cuz it is so thick, and cost quite a bit, but it does perform, I gained, .8 db from using dynamat on my roof, then put a layer of treo mat over that and gained another .3 db on a 20 degree hotter day. Placement is my view on where to gain when using deadener.