Solid 'Wing' sails?

I don't know enough about the fine detail of the Laser performance to be able to comment much. At an utterly uninformed guess the boat would probably be a bit faster upwind, a bit faster still crosswind, but maybe not improved running. Oh and do 500 quids worth of damage every time you capsize...

Was it faster ?

They didn't win.

I don't think anyone is in doubt that the solid rigs are potentially faster, especially if there was some relaxation of the Moth rules which prevent slots in the rig. Whether they are a good thing is another matter. There's the awful example of the C Class, which has been the most interesting and technically sophisticated class on the planet for the last 40 years or more, but also perpetually balanced on the edge of extinction because so few folk can afford to campaign them.

The purpose of class rules is, after all, to enable people to have fun competing in sailing boats, so if next to no-one can afford to compete then that suggests a problem with the rules.