Update and brief review:
Received it. Put it together. Hooked it up. Tried to use it (dry steam) but the silicone (vinyl?) tube blew itself off the hose barb (not the steam wand). Ghetto rigged it with a twist tie, and all was secure. Have subsequently upgraded to three (count them, three) plastic wire ties, for that "'Klassy' with a capital 'K' effect." Should you want to soften the steam-punk-kludge look farther, you could use high temp sealant.
People here and in other fora seemed concerned about the tube possibly blowing itself off the steam wand. If you're not careful, it does. However, as long as the silicone tube is pushed up close to the wider part of the tip, it will not come off, at least not on my machine. Unfortunately, the higher up the tip you push the tube, the more of a beast it is to remove from the wand. You may have to pull fairly hard, which means supporting the steam wand so as not to pull the wand from your machine, but (surprise surprise) steam wands get hot. If it's really stuck, let the wand cool before removal, run some fresh steam through it so the heat soften and expands the silicone, then use two towels.
This thing REALLY REALLY works. It leaves the group raceway, gasket, and screen immaculately clean; and of course you can use it to clean anything it can reach. On the other hand, because it takes so much time to set up and put away you'll probably want to reserve it for end of the day and continue using your regular brush between shots for those inter-shot times you want to brush. It's a large PITA.
Worth it? If you're seriously into clean, AND you can afford a $75 brush, AND you enjoy complication, AND you like buying gifts for your espresso machine, it is. Otherwise, no.
I like mine.
Drop a nickel in the pot Joe. Takin' it slow. Waiter, waiter, percolator