I see I am late to the party and hope Amelia is still here.
I am with you, the idea of the composting head makes so much sense.
Amazing what we put up with as no big deal and find hard to switch from.
Not having a home on the water means having to pay for pump outs so it is safe to say as a live aboard the composter will pay for itself easily in 2 years.
Putting in a new fresh water tank is another bonus.
It has been several years since you posted so wondering if you got an Airhead or similar and are you happy with it still?