Also, why the plastic ball on the end of the sheet, visible just behind the block on the jib?
I saw that too - and I think it is an answer to the question I pondered previously. If the user wants to maintain more tension on the jib without it coming inboard so much (i.e. higher wind), you hook that ball into the spring clip located on the travler.
Err, ok.. If I have got this right then, this jib setup has two modes besides what you can achieve with sheeting. Low and high wind setting, adjusted by increasing the purchase between jib and track.. I begins to sound a bit complicated to me, as compared to the curved track with stoppers.
Would be interesting to do some two-boat testing, and see if the auto-adjustment feature of the straight track was faster or slower in the pure boatspeed sense (perhaps you already have done so Bill?).
Wouter: Yes, I'll do some testing with increased purchase between the jib and jib-track when the season starts again. Altough we are quite satisfied with the simple and powerful cascade system we have today.
The original question seems to have been thoroughly answered by now tough.