Fish -
Check out the thread below. Lots of opinions on the topic and this was a good synpopsis.
https://www.ford-trucks.com/forums/s...d.php?t=338480
The Dynamat is very pricy. Also, I recently saw something very similar in the JC Whitney Truck catalog that looked very similar (alum faced, glass reinforced, non-absorbent, etc) that was much better priced.