seems like most people commenting on this have no experience with them and don't know what they're talking about. tons of people use these in RV's and boats. the toilet only weighs 35 lbs + whatever waste you add to it, just like your normal toilet, only there's no water to flush so it's actually less weight. you can store about 2 weeks of poop from two people.
1 and 2 are separated so there's no sewage smell. 2 goes into a bin with sphagnum peat moss or coco fiber where it starts to compost immediately. not saying it's odorless but it's not a pit toilet, people. they're legal and safe.
this airhead model is a few inches smaller and has rounded edges compared to the natures head that the wynns show, could be important since i'm sure space is at a premium.
sorry i don't have much personal experience with them but i'm considering adding one to our camper so let me know how yours turns out. i'm just frustrated at everyone continuously shooting this down with no personal experience like you asked for.