Not sure how anyone can compare this to a CNC machine:
1. This is portable, so I can take the tool to the work. That's a significant advantage for some kinds of activities.
2. It appears to be an add-on to a router, which most people already have
3. I suspect this can be packed up and stored away
4. The size of this machine is not dependent on the size of the piece you want to work on
I guess this could be all moot anyways if it's not possible to purchase one yet. Regardless, I can think of many reasons this would be preferable to people over a CNC machine.