A knowledgeable RV'er/Poster with a Country Coach, is pleased with the sound reduction of this product. He's put it on one unit, and will do the rest now too...
It's on my list to do too... One downside, only white color is available, so for those with beige/tan color roofs, a trip to Home Depot for a paint to match is an added step.
I'll note, that I do not know how this will work with AC's that have defused returns to the unit.
Best to all,