so, actually i was lucky with the wind this weekend
at lake silvaplana, it was blowing 4-6 bft , i was out with my 16.5 gxr almost 8 hours, so i can tell you more about the board.
overall impression (as far as i can tell after 2 sessions on it)
most importantly, it works! the more overpower, the better. as with most boards, you have to get used to it a bit to find the right position of your weight.
to make it going, you have to accelerate it a bit more than e.g., my 140* 40 board, i.e., going 20 meters or so slightly downwind to pick up speed. probably due to the very concave bottom, there are like 2 stages, first, you get out of the water, and second, a „turbo“ kicks in.
once on speed, you can edge as hard as with no other board i know, and you go upwind at an incredible angle. (under the condition that you have power in the kite). because of the excellent edging, you can handle overpower incredibly well.
on the other hand, when it is gusty and the wind decreases immediately, you just sink (no wonder given the small size of the board.)
do to its small size the board is very loose for switching. to jibe it, you need a sensitive foot as it reacts very quickly.
the jumping ability are of course cool: you can really load the kite, and you don’t even feel the weight of the board when the lift kicks in.
in conclusion, my hopes that the concept of an ultra thin, ultra concave, very short & wide board would work have been confirmed