Re: Composting Toilets vs. Holding Tank
Good points above^^^^, plus the installation of a composting toilet is very much within the abilities of any unskilled boat owner, while a wet toilet, holding tank and all the fittings etc. is a much bigger and more difficult task. If you have to call someone in to install it, it will most certainly end up more expensive than a composting toilet.
The C-head is cheaper, as someone has pointed out, but I think you should compare it very carefully to the Nature's Head before buying one. They are both good products, but not really an apples to apples comparison.