Simon
The self-tacking jib is the best think since sliced bread. Upwind doesn't make much change unless you have a new crew ( the tacker will tack the jib perfectly each time). Downwind is the real advantage. The crew just has to worry about the spinnaker not the jib. It also helps me. When I get the perfect angle downwind, I am able to jibe and get right back on that same angle because the jib was never adjusted.

On a side note: I heard the the F20 class in EU is thinking about bring the sail area up to the North American numbers. Peter Vink has sailed the boat in the North American form and liked the extra power.It may be BS but interesting at that. Now wouldk be the time to change it because there are only two F20 boats out there.
Barry