deadening

[headbussaboi 10+ year member]

No, it's one of the best in the business. They can charge $1 or $1000, it doesn't change the fact that it's a proven, effective product.
Both are garbage. Dynamat Extreme is miles above and beyond both. Both would have trouble competing with the original, even.

I've used Dynamat Extreme and would not pay the asking price for that bulk pack. It's not user friendly, cuts your hands to shreds, and cost alot. There are products that will get the job done just like DE, for a fraction of the price. Is Dynamat effective? Yes. Is it proven to be one of the best in the industry? Yes. But with the pricetag it carries, most of us want to be able to do get the most out of our money. I've never had to use 2 layers of deadener in any of the many installs I've done, so to me, it's all a matter of if it sticks or not. I'm nowhere near the point of having so much flex that I'll need that much. I'd consider buying something different unless you had the money to spare and wanted it done right the first time without a doubt.