I give it two thumbs up.

I have the 14x27 flat water carbon board.
Two things .
One: it is relatively heavy for a flatwater carbon board at 12.8kg without fin. That MAY mean it is a bit stronger, but as I needed it for racing I am a bit disappointed ( my Deep dryft is just over 9).
The other is the shape is relatively inefficient. It makes a lot of noise in flat water and you can feel the drag and see the wavemaking. As it is an interim board, until I can get my feet and lower legs stronger for the narrower Deep, I am not too worried.
The downwinder may also have the same no concave or v shape in the bottom which makes it a little harder to get moving. For a downwinder that may also not be as much of a problem.