Hobie 16 Police Here:
Wouter has opinions, that's good. They can be interesting.
Some facts from memory are that 8 of the top ten at the recent alter cup all came from sailing a non-spin Hobie 16,18,or 20.
Edit: (Forgot Bob C on the 14 and 17)
Last years F-18 championships top 3 again came from non-spin Hobie boats. Second and third were both Hobie 16 sailors.
The current Tiger world champion came from the H14 and H16.
He won both those National championships also.
The bottom line is that good sailors/racers can learn on about any boat.
They also have a feel that can never be taught.
Think Carlton Tucker or Enrique
Technology doesn't change the need to understand sail shape and what makes the boat go.
Racing is how we can judge boat to boat.
To be a good racer, you need to know how to start. wich way to go, how to cover boats, how to round marks, etc. etc.
All this can be learned on any one design or Formula boat with spi or not.
It does take time to learn the spi boats, but my observation is the good guys and gals pick it up quick and are back in the top of the pack.

My opinions.