Anybody use Flatline Barriers interior insulation/sound deadener?

Curious if anybody has used Flatline Barriers insulation/sound deadener? If you have, what did you think of the results?
Flatline Barriers | Individual Interior Insulation Kits

They have pre-cut kits for '67-'76 Dart, Barracuda, Demon/Duster, Scamp, and Valiant.
The price seems reasonable and the videos show good results.