Sorry to start this topic by talking about toilets, but when it comes to plumbing, they're the most trouble.
For years we struggled with an assortment of heads, first using a chemical one that worked fine until we locked up the boat in the hot tropics..Pee-yew! Then we went conventional and suffered the usual leaking pump glands, and busted diaphragms. Years later we used macerating electric ones on our charter boats and ran into the worst trouble unblocking the dang things. Jeez, my worst nightmare is a summer in the Mediterranean, earning our keep by fixing rich folks electric toilets. Recently we had a stint on a rich man's luxury vessel equipped with a vacuum system that was great if you've have a lazy million to keep it working and an 80 footer to house the hardware.
For cheap cruising, the trouble free solution is something like a Lavac which uses a robust, large valve, pass anything bilge pump as it's only moving part. Simplification to the max. Cheap Cruising says a homemade lookalike can be made out of spare bits. We had an old porcelain bowl, a spare Henderson Mk4, and made a sealing seat and lid, then connected it up with 2x three-way valves so we could direct the outflow overboard or to our holding tank, and still use the same pump to empty that tank.
Ours has been in live aboard service since 2007 and has never-ever clogged! Attached is a photo of the unit from Jude's Practical book (http://jackandjude.com/banyandah/head/).