Mine is the Jabsco - Quiet Flush Electric Head-Raw Water model. I see it advertised for $659.99 at Boater''s World. Others may have it for less.
It has been perfect to date. At the end of last season I was prepared to disassemble the plumbing because water flow was seriously reduced. Turned out to be a discarded "item" lodged at the drain by a lubberly lady (we can leave it at that I assume?).
I meant by "nasty job" only what you would expect anytime you have to tear into the "business end" of a toilet. Fortunately for me that job is still off in the undefined future.
In any case, I encourage your idea to install an electric head in your boat. Assuming the installation goes properly - the operation of the head is very simple and much more "intuitive" to non-boating friends. Its dependability has been a very pleasant plus for many - myself included. Even with the macerator however, it is not intended to dispose of anything other than, ah, hmmmm "organic" and tissue materials.