My information is second hand but i think it's pretty reliable.

Marstorm's goal was to make the NEXT olympic catamaran. ie a boat that was a highly refined machine that the best sailors in the world could really use to sort out the best sailors at the Olympic and World level.

He wanted a boat where the team work in adjusting the rig and sails and gear changing going up wind would determine who got to A first...the goal was to make the boat as tactical as possible ... so the boat needed to tack like an A cat and give you total visiblity of competitors and wind ... That meant he went unirig. I think this point matches what Hakan just wrote with respect to the windage factor that marstrom considered.

If you dig up the results from Querbion where the possible replacements for the Tornado were evaluated... the Olympic test sailors thought he had succeeded in building this boat.

Now... the world has not really caught up to the class or the features of the class are not that importand and so the boat is now seems to be used in as many distance races as buoys races and so the faster version has the jib.

(the verbal argument of whether the jib addition adds or detracts is thrashed in another thread)