I'm sitting here with real world experience as I type.
I installed an Atwood Air Command in our 5er, and right now both it and the Dometic Brisk Air OEM unit is running. There is a ton of difference between the noise each makes. I wouldn't say that the Atwood is quieter than the Dometic (though I think it is), but the sound profile difference is amazing. The Dometic makes a highly irritating noise. The Atwood even on high can be talked over and it's easy to hear the radio and TV over.
When I replace the Dometic it will be with an Atwood.
Salem 29RKSS Pushing a GMC Sierra 2500HD!
Gotta go campin!