We have two heads. Initially two old jabsco manuals, leak like sieves. Replaced with two manual PHIIs. Great head, bullet proof, easy to replace jocker valves ect. Replaced aft head with Raritan Seaera electric which goes to a Electroscan MSD and the to a Y which goes overboard unless we are in a NDZ, then to the holding tank
We chose the Seaera because
-Simple design, easy to unclog and macerates.
-Easy to replace jocker and macerator blades.
-Have had very good support and Raritan has a good reputation.
If I only had one head, and cruised a lot away from US then would probably stick with a manual head.
If you want electric would recommend a head that was designed as an electric, manuals with an electric drive installed do not last long. problem is that when you hand pump
you can feel if there is a problem/jam, you cant if you are pressing a button.
I might be biased but I believe that Raritan is the top company when it comes to Black water marine systems. Their designs and support are excellent and they have probably the best good quality marine heads without being excessively expensive.