OK - we've had a composter as our only loo for the past 5 years. We started off with a Biolet - can't remember the model, but it was one of the type with an electric powered stirrer. It stopped working after nearly 4 years, and we couldn't work out what was wrong, so we made the ungreen decision to ditch it and buy a new one.
We now have an Envirolet with a manual stirrer.
this one
There are 4 of us - me a SAHM, two school aged dcs and a partially working from home dp.
The first thing to say is that it really needs managing - it doesn't take long, but you do need to keep an eye on it all the time. It doesn't smell unless the composting process goes wrong - which it sometimes does.
We have found that the composting process is rarely as thorough as the manufaturers claim so emptying is a smellier and more unpleasant process than they would have you believe! We empty ours every 6 weeks or so.
You need to have some sort of back up - we have a portapotti - because the longer you leave the composter unused before you empty t the better - manufacturers say 24 hours - I say at least 48 if you can.
Downsides. Every now and again it goes badly wrong and that is GRIM! It's happened twice to us - imagine liquid sewage on your bathroom floor and having to mop it up. Both times it was due to us getting it wrong - but it will happen, so be prepared - and think about how traumatized you'd be by this. I was fine, but I am very unsqueamish. Dp was rendered completely useless and gibbered helplessly in a corner.
However, all this said, we are very happy with it. 95% of the time it works so well that we don't think about it. We haven't had a problem with visitors - small boy visitors particularly enjoy looking down into the mix and claiming to recognize their poo!
I hope this is helpful - and not too jumbled. More later - as I said feel free to ask questions.