Terry,
Another factor in your decision should be wether you have the compressor to use to spray on the Lizard Skin. I was planning to use Lizard Skin because I really think it has the most flexibility and EdwardB's build thread provided an excellent path to getting it done but in the end I went with Dynamat Extreme because I lacked the compressor.
I also looked at other lesser products and went with the DE after reviewing some issues with running of the butyl rubber when hot, etc. Like EdwardB said ... your spending a lot of money on the rest of the car so why go cheap now on a critical component.
If you have the equipment to apply it based on my view it is less expensive and easier to apply than the DE type product. You spend a lot of time templating and cutting the DE type product...and if you screw it up like I did ... you end up with some wasted pieces.
Just my two cents ...
Carl