We had one on the boat for several years.
For more typical RV use (ie: limited boondocking of a few days or less), tanks are much simpler and easier to use.
If you will be boondocking where you can't drain the tank for longer periods, they can be advantageous but usually, you will run out of fresh water about the same time as the traditional tank systems fill up.
Probably the biggest issue is what to do with the urine tank. It needs to be emptied every 2-3 days (assuming 2 people). If you are camping where there are toilet facilities, it's viable as you can pour the liquid in the toilet. Just dumping it on the ground is likely to get you some nasty comments if you are caught.
Odor is one of the biggest reasons to get one (though not so much of an advantage in an RV...boats are notorious for smelly heads but the plumbing is much different). If there is odor, you are doing something seriously wrong. They are pretty simple to use correctly. No you don't want liquids in the solids tank but they are designed to separate.
- As mentioned, liquid tank is emptied every 2-3 days.
- Solids we were good for around a month. Usually, it would be bagged and put in a dumpster (no worse than baby diapers...actually less offensive). Assuming you can let it compost for a couple days, looks and smells like rich earth when emptying. If you can let it fully compost (a couple months), it's great for the flower beds.
Tammy & Mike
Ford F250 V10
2021 Gray Wolf
Gemini Catamaran 34'
Full Time spliting time between boat and RV