Having owned a Tiger, two pre-Infusion Nacra F-18's, two Infusions, and recently spent 5 days racing the Capricorn at the Alter Cup, I'll chime in with my 2 cents worth.

The Tiger seems to be faster upwind in light choppy conditions however it has the heaviest feeling helm of the bunch.

Pre-Infusion Nacra - Good upwind speed, but lack of bow volume makes it pretty easy to pitchpole in heavy air/big sea conditions.

Infusion - Good upwind speed, large bow volume allows you to push it harder downwind in waves. Very light helm feel, very responsive.

Capricorn - Overall construction quality is best of the bunch. Very balanced upwind. Downwind a little "twitchy" due to the large rudders. You've got to be very gentle driving it fast downwind. Less bow volume than the Infusion makes it more likely to pitchpole. It happens very fast when it goes down.

Overall, you cannot go wrong with any of these boats. There are such minute differences in performance between the platforms, that it still comes down to the sailing skills of the crew to determine the winning boat.