I am beginning the hunt for a replacement 155% Genny for my Hunter 23. The sail will be used for racing only. Does anyone have experience with 3DL sails in this size range. Is there a noticable speed improvement? Is it worth the extra dollars? If you put a window in the sail, does that eliminate any gain you may have had in the improved performance? What is your opinion of windows in mylar sails? Any comments will be welcome. Lets just talk about the sails, I am completly aware that skippers win and lose races, sails don't. Thanks, Bill Leathen