I tend to stay away from the flourescent lines. There just seems to be something wrong with using a flourescent grub (ie: black/chartreuse tail) to attract attention and then putting it on a flourescent line, which we hope will not be suspected by the fish. I use the most invisible line possible, especially in the clear late fall and winter waters. I can still see it above water. When you are on agressively feeding fish I don't think it makes much difference (You know, when the fish hit the lure on the drop). When fishing is tough and the fish are not aggressive I think it matters greatly. Just my 2 cents.