From my research
, it looks like the Air Head
is the way to go. I'm not a fan of holding tanks
as an Ex-RV'er. The Air Head processes urine separately which I like. In one review I read it was suggested you could plumb the Air Head to have a holding tank
that only held urine; I'm not to keen on that but some might be. I used to be an orderly during my university days, part of my job was to empty the catheter bags just before shift change, so after emptying many thousands of gallons of urine - no big deal.
I did check the composting toilets thread; it was useful. Here's another link:
Upgrading my Marine Head - Installing the Air Head Dry Toilet by Charles Kanter, AMS