Gary,
Looking at that video it looks very gusty, hard to get the power set up well, and they look like they are struggling just to keep the boat upright. Not good for speed.
I think catamarans can sail at up to 1.7 times windspeed in 10 knots, probably close to windspeed in 20 knots, and a quarter windspeed in 30knots (daggerboards make very small sails )