If the end of the leech is attached to the end of the boom, which is on the deck when you are block-to-block, how can you increase leech tension by adding more vang when you are already sheeted block to block? It would seem to me that adding more vang might increase mast bend, but since the position of the end of the boom is fixed on the deck when you are block-to-block that would loosen the leech. It was my understanding that the purpose of greater than block-to-block vang tension was to prevent the boom from lifting as the sheet was eased, thereby preventing the sail from becoming fuller when easing the sheet (in a puff in heavy air, or when playing the sheet in waves etc.) Anyway, I could super-vang without any sheet tension with the old (mid-90's) vang setup of rope loops. My current vang setup is 6:1 with the old blocks and additional blocks instead of loops. I can easily super-vang with this setup also. The only convenience of the new vang hardware (beyond the unnecessary additional purchase) is the better performance when pulling from an angle, such as when hiked out. When I set up my 6:1 vang, it seemed to work fine, so I have kept it that way. I get funny looks from the young-uns on the race course, but I also have much less vang line floating around on my deck and in my cockpit because of the lower purchase.