In the above pictures, it's not possible to measure and compare twist empirically (Unless you get really fancy by measuring the boom on the F-18 and write a program to remap all surfaces..) But you get an impression of twist distribution and amount. I tought it funny that the F-18 was sailing with what looks like similar twist as the A-cat. But the discussion is about differences in design and flying shape for uni rig mains vs. sloops.