Yep, I use one on all my jobs.
Works extremly well.
Dont know where you get the info they are heavy!

Did you see the roller on the back? That helps on the forward stroke - no need to lift the wand off the carpet just tilt the wonderwand down a little and push along.
Have you seen the adverts for the glides that fit over the lip of "conventional" wands - thats to help get better suction and ease with the movement of the wand.
No need for that with the wonderwand.
I have had mine for 17 months now and replaced the little washers around the jets at its service a few months ago. If the jet-bar is not seated proper you will get leaking fluid but thats an operator "error" easily cured (fit the jet bar properly).
They are expensive but a good joiner (or any tradesman) will spend good money to get quality gear that will enhance his skills - so why not a carpet cleaner??
Oh yes - they do leave the carpet fairly dry as well.
Its win win time.

Which machine are you getting that you want to use this with??