What is everyone's opinion on sound deadening insulation, like Dynamat?

 

I think it's great but, don't buy the one that is made for vehicles (too expensive). Go to Lowes or Home Depot and buy the insulation they have for home ventilation systems. It comes in rolls with a sticky side, for about 17 bucks a roll. It took two rolls to do the floor, fire wall, both doors, and back wall inside the cab of my 68 chevy pickup. Works great and I saved lots of money. I used some spray adhesive for a stronger hold.