We've regularly averaged in the 20-22 kt range on the N20 and F18. Top speed has been reported at 30kts. I suspect the real world number is in the 25 kt range, well I've seen that in flat water and big breeze.

The C-Class shown above has reported 27 kts. I suspect we'll see those guys pushings 40 kts in a straight line.

The Flying Phantom is the 18 foot, F18 Phantom hulls built in carbon, platform widened and full foiling added. They have said 30 kts is well within reach for that platform and it is noticeably faster downwind than a stock F18.