I fished WarrenP's Berkley Gold Vanish furled leader while highstick nymphing a few days ago and I thought it worked beautifully. The gold color makes the leader easy to see where it enters the water and it seems to sink quickly, which I certainly like when nymphing. I used a 4.5-foot leader and he is generously going to send me a 6-foot leader to try. I caught enough fish to make me happy and just as many fish as my body who was fishing a regular leader. My main concern with furled leaders is do they create a belly, and do they cut through the water and sink quickly.