Wouter,
I think the difference in your experience with the FX1 is the same thing we have noticed against the F18s, that in certian conditions with big chop and relatively light air, the extra weight of those boats helps them through the conditions. Not necessariliy the hull shape.
There were some very good reports on the Capricorns from the Worlds that play off this same argument. The Capricorn shape is extremely similar to the Blade. They lacked the level of professional drivers racing them, but still had quite a few boats up near the top.
Like Wouter said, no boat will perform perectly in all conditions. I am very sold on the new hull shape, and feel we have an advantage in upwind performance over other boats in most conditions.
M