Yep, got one but a different model. My toilet looks very much like a domestic toilet (an not a small cake mixing bowl on a stick) and the tank is curved to fit against the hull. The complete setup is not cheap but very reliable. I have a watermaker so I run freshwater through it. The only thing is doesn't like is DRY toilet paper. But it can easily pull half a bowl of wet toilet paper (plus some other unmentionable stuff) from the bow. The narrowest part of the system is directly below the valve (bottom of the bowl) and can be poked with a long screw driver if someone decides to try putting dry paper down it. Very happy with mine.
If you do get one, my only advice would be to find toilet hose with a smoother interior and heat it to make it soft before tightening the hose clamps. The system needs to create a vacuum and hold it prior to flushing and any sort of leak will be counterproductive.
www.seabreeze-industries.com.au/products/SailVac-5200-Vacuum-Holding-Tank-554.htmI would imagine the guys will be a the Sanctuary Cove Boat show this weekend if you are in the area.