That is right Håkan, but how large is the difference? I think the rig/sails will still be a far better powerplant than another design. The amount of development going into the Tornado rig/sails is immense and the rig/sails are far better than a "special" design. I did not say anything about lighter hulls, hard to amateur build cheaply in wood below 165Kgs, so righting moment will be approximately the same and hence also gust response. Then what's left is the difference in prismatic coefficient for the hulls and L/D+effectiveness of the foils. Also consider that the rig is very well known, so you know what is going to happen when you start tuning it.
I think the rig will be superior on a new platform, and hopefully we will find out soon.