Steve, Thanks, appreciate the info. Their prices do look good and they have a good reputation. Interesting that I have not gotten any response/info from people on the D-4. My sail maker had one he just got in to trim, etc. They really look great. The fibers are supposed to follow the force, load pattern in the sail. Makes sense. Kind of similar to finite element analysis, the number of fibers and direction corresponding to the loads in the material. I would just like some input on other sailors' experience with them.
Thanks, Chaos