It sounds like a pitch to investors. They must be having a hard time finding sponsors. I can understand why too.
The planes go considerably slower than I thought they would. No faster than a propeller driven plane (218 mph was listed on their website). It's basically the red bull air races except slower (red bull is up to 265mph) and with rockets with limited fuel.
Note - Nascar top speed is around 212 mph, Indy car average speed is 220 mph at Indianapolis, and formula one can also top 200 mph at the end of a straight on many courses.