From the best of my knowledge, it is one of the older General Electric models, but has a newer, most likely Dillon Aero, barrel and possibly other parts on it. Hard to be an expert on something you've never seen before though. The barrel keeps the flash down to basically zero, so there's just a huge gust of wind that comes off of it while firing.
Calculated it to be firing at 58 rounds per second (3480 RPM) from the 600 frames per second footage. Definitely the most expensive gun there (and they actually had two of them out on Saturday).