We just changed over to an electric toilet with a waste treatment system. We are full time live-aboards and so the system gets a lot of use.
We have the system in use for only a month or so and so far we are very happy with it. I love the electric toilet. Uses about a pint when you flush just pee. Uses about a quart to a quart and a half for the solid waste. The electric toilet has a built in macerator and so you can get away with a 1" waste hose. No pump-outs are required.
We still keep the old RV flap style head with the built in tank in the aft cabin. We use it if we should encounter No-Discharge Zones. If you go with a Type 1 Waste Treatment System, make sure they are legal in your area.