This was showcased at a demo today, and as a prototype, it is bulkier and heavier than a production run would be.
They said that they have only made two of them, mostly because Mr Geissele thought that they were cool, but that they doubted that there would be much interest.
What do you guys think? Remember, a production version would be smaller, lighter, and likely QD.
I'd actually like one. It would be perfect for my 15" rail.