I have to admit, I really,
really like that design, especially using what amounts to kayak-cloth fairing for the lightest possible weight and some decent protection to the passenger.
The 'stopples' I see in the second video do concern me a bit though-I wonder if lowering the passenger roughly two inches and elongating the frame another six would add some stability? Mind you, i'd buy one as is if-
A) I had the money
and
B) The US didn't have this 'Four Wheels=Car' mentality.