I just purchased Soundown direct from the company. Great service, lots of help in choosing the right product (they have many) and advice on installation
was relatively easy but I bought the thickest, heavies grade and holding it up during installation was a bit tricky. If max ease installation is your preference other companies make insulation
in 12" squares.
Unfortunately I have not yet launched so cannot report first hand on how well it works. I can say that several years ago Practical Sailor did comparison tests on insulation
from several different companies and Soundown came high on the list if not the best.
Tell him you were referred by Skip in Gainesville FL and he will double your price
and give me a kickback (only kidding but do give him my regards).