I saw this fly in Belgium last year at Pampas. It is certainly the fastest thing I have ever seen, and I can assure you it would not be close to legal in the USA. It looked wickedly twitchy to me in flight and I was at once impressed by the undoubted skill of the pilot, and agast that it was set up so twitchy considering the blistering speed! Outstanding to see though.
Regards,

John