The formula boards have been racing on the same course with the kites this year in the SF Bay. The kites have made huge improvements in upwind speed with the quad fin, now three fin setups on the new wide style race boards. Downwind the kites are much faster, because they can go nearly dead downwind. They have given up a bit of speed downwind with the new boards.
On a short race course, the transitions make a big difference. Tacking a formula board takes a long time. The kites can tack pretty quick. The formula boards have a slight edge upwind and much slower downwind.
In the typical 18-24 knot breeze the best kiters are beating all the formula boards on a course with a 1 mile upwind leg. The power to weight ratio is higher for the kite.