Been using the new PW I got and I have to say I do like it. Definitely not 100% necessary, but it is a "nice to have" type of thing. Besides, it DEFINITELY helps get the dirt and caked on mud off of my truck (my DD)
The good thing about the Clean Force one I have is that it doesn't take much time to set up at all. Plug it in, attach the hose, and you're ready. The cords and hoses are conveniently wrapped up and it comes with them on spools internal to the machine. Setup and tear down time is very limited.
Overall I am happy with the purchase. Some of the tough to get off bug splatters and wheel mess come right off with the spray. It makes rinsing extremely quick. And like I said, definitely not necessary (especially just for an M), but a nice to have tool. I find it more useful for my truck though