Hi BJ
It was good, once the owners got it to work. It had been installed incorrectly by the dockyard at Port St. Louis, and there were a few days of irritation. But the ever-ready Paul took the thing apart (whilst the rest of us left the yacht for a while!) and from then on it worked a treat.
No holding tank needed if it is working, and this one worked once Paul had sorted it out. It was fairly quiet, and did the job it was installed for, without eating many amps or smelling.
My view of the thing is that it would be useful on a large boat with sensitive owners. I'm not so sure about the average size family yacht. For me, simplicity is everything, and whilst holding tanks can be a problem if you don't treat them properly, they are fairly straightforward in terms of function. And they needn't smell if treated right.
We found ourselves staring rather too often at the LCD display messages, wondering if they could be hooked up to the Navtex so we could use the loo in advance of strong winds, and generally trying to work out what the messages meant. My advice is not to fit the LCD display where the yacht's crew and guests can see it. Staring at the message 'Ready to Flush' over dinner didn't seem quite right, somehow. Stick it somewhere less obvious than the cabin forward bulkhead!
I also asked myself what would happen if the thing got terminally ill and there wasn't a holding tank on board.