I strongly recommend to anybody thinking to buy one of this to FIRST demo the board. This board is very different regarding shape and materials. So, your normal volume, shapes, fins might or might not work for you.
In my experience, I went little high in volume. I normally surf with 30.5L, so I was recommended to go with less than that, but I went actually higher with 31L expecting an extra paddling power in power waves. However, on one side, I felt lack of paddling, and on the other side I felt a very good buoyancy to perform the turns.
As a conclusion, this is the first board that I know I went wrong with size, however I don’t know if I should have gone higher or lower. So, I will have to demo the 5’7 and 5’9 to have a final verdict.