Kitesurfing Denmark, your pics just came up on my machine,..boards look great,..now I understand your spoiler. Looks fast!
Until now we have only experimented with twintip boards. For "standard" twintip boards Spleene Door is the best upwind going board we have sailed on yet. But in wawes it is very difficult to go downwind fast. The fronttip of the board goes into the waves and you crash! Therefore we have made the modification with the spoilers, to prevent this. The board wil works its way out of the wave again, because of the spoiler.
As you can see from the pictures we have also cut some of the board in both ends. When you are going upwind this part of the board has no effect, but going downwind it eysier holding the board like at Speedboat on the wather (keep the nose up). If the board is very wide at the tips, this will be more and more difficult as faster you sail.
The changes I have made on the Spleene Door 64 you can see here:
http://www.surfsurf.dk/Spleenecostum/Sp ... costum.htm
We are still experimenting. Today I have change the hadlegrap out with a extra foodstrap, and will try to use it both upwind and downwind. I do not know if it works yet.
The two boards on the pictures are until know the two wining boards in Denmark, but we have also some guys using directionals, and they are doing good to.
I thing the dicetional have some advanges in courses at open see were the waves are big, and specially if the course is long. In smaller waves and smaller courses, with a lot of "turns"? the twintip perhaps is better.