I do not believe there is any difference between the f/c line and the f/cleader material, kinda like the way the Maxima line and leaders are spooled. This material is very different though and is best used with a specific purpose in mind. Not only is it expensive but it has some unique properties. More "invisible" than many lines, it sinks and it is hard to tie a strong knot with. Only thing I use it for is fly leaders when chironomid fishing where the fish are line shy and I want my bug to get down quick. Otherwise I wouldn't bother with it. It might be alot more expensive as leader material because most people want to buy it that way and very few people use it as mainline or in bulk.