Actually, the I 17 (I17R) has the same set up as the I 20. You can set rotation anywhere from about 0 degrees to 90.

Tom

Martijn,

A good place to start would be about 45 degrees for upwind (and decreasing as the wind comes up)and about 75 or so downwind since you will be wildthinging I'm guessing. Some of the others sailors may know better on the downwind. I have been sailing with a spinnaker the last three years.............

The Taipan website above spells it out for light, medium, and heavy winds.