Without doing to much research those results suggest it is definately competitive. Given the top 10 is typically full of sailors who could win F18 races on a hobie 16, to get those results even if they are great sailors suggests that like all the other f18 boats it will be the guy/girl holding the tiller that will make the difference.

F18 really seems to be producing the desired even playing field. Right now given enough skill, you could happily expect to get good results on any of:

Tiger
Infusion
Capricorn
Wildcat
Exploder
Shockwave
etc