Wouter,
First of all - lighten up
Second the VX40 website says "max" speed 40knots
Third if a soft sail Crossbow II went and AVERAGE of 36knots in 1980 on a 500M course, what makes you so sure a VX40 cant hit 40 for a brief moment or two?

We've had 26 years of technology since Crossbow to add 4knots? I'm thinking this isnt beyond belief. Its a rather extravegant claim, but its not necessarily improssible.

You've never sailed a VX40 - right?
You've never seen one sailing? (in person) Right?
Have you even seen one at the dock?

What makes you an expert on how fast they can go?

Bill