Do not know much about them short of if they get water in them you can drain them easily.
That,and Rowen Law seems to be getting going crazy early on his new Patrik hollow board,not sure what size it is.
Heard they weigh around 5kg and that they cost 6K. Though the cost is seemingly set to drop to 4K when they get the production down pat.
Might be harder to control / keep down in the gusts at that weight.
Only ever sailed a 5kg board once,a Windtech and it made a big difference to the feel of the board.
Could work great for foiling too.