I really like the idea behind this product. I find the accuracy of your holes to make a real difference, and cut-in boxes have just enough things poking out to make any simple rectanglular hole somewhat sloppy- resulting in a box that can wiggle in the hole.
In short, as I see it, it is the templates that make the system.
Integral dust collection is also a plus; on some jobs, it's simply critical. I've had ninnies complain about "dust in the air" hours after cutting a single hole with a hand saw- even though I vacuumed immediately!
Likewise, not every vacuum will survive an encounter with gypsum dust.
As for powered cutters, I have had mixed results. Some throw a LOT of dust into the air. The Dremel just doesn't seem to have enough power. All of them make it far to easy to either cut into a pipe in the wall, or straddle a stud with your hole.
This guy just might have something really useful!