I use them on and off. I really like them for dry fly fishing because you can be "a little off" with your pick up and not "rip" the surface. Having said that, I had a guide on the San Juan tell me he didn't like them at all for nymph fishing. He was convinced that the "ridges" created by furling create additional drag issues subsurface. His point was river specific. In other words, he was saying the fish on the Juan are soooo picky that any chance for additional drag makes a big difference there. I don't know what to think other than to say I seemed to have more success when I went to a traditional leader. For what its worth.