OK ... I didn't study the whole website, but isn't this just a fancy wag-bag
The way it works seems kinda cool, but I certainly wouldn't want one on my boat. First off, while the mechanism seems interesting, it looks complex. When the vacuum fails or the twisty mechanism dies, you'd be in trouble. The volume limits (~15 deposits per bag) are pretty small in my books
. You are required to use proprietary bags, and I'm not sure I'd want to put my faith in bagged liquid sewage if it had to be stored on the boat for any length of time.
From my brief look, I'd say any of the composting-style heads would be a much better option. And yes, I have one (Nature's Head).