They seem to be the unit of choice, and they do need to be vented. One thing that surprised me was the last picture (diagram) I saw of one, it had a 3/4" discharge. Seems small, even for macerated waste.
If you have never made a mistake, you haven't done much.
I've installed one last year for a client and it's a pretty sweet little set-up. A little different from a normal WC install, but once I got my head around that, it was pretty straight forward.
Venting is just like tying into a current vent system.
The reason that there's only a 3/4 discharge pipe is that Saniflo makes macerating toilets. Here's Saniflo's description of what one is: "To "macerate" is to soften, to break in pieces. Our macerating systems use a rotating cutting blade to liquefy human waste and toilet paper, that when mixed with flushing water is pumped into a sanitary sewer as a fine slurry."
I've haven't heard a peep from that client so I imagine that it's working well for them. Since it was a attic conversion in a 100+ year old house, a traditional drainage system wasn't in the cards for them.