It is one of those things that seem cool, but then I wonder how I could apply it. You can’t use it to cut the tag end of a knot. If a fish was gut hooked it might come in handy, no pun intended. You could just cut the line quick and return him without putting more undue stress on the fish. Outside of that, I don’t know how I’d use it.
My point? I don’t believe in cutting of tag ends unless the walleyes are extremely fussy that day. Sure it looks nice with them neatly trimmed, but the fish will still bite with an inch of tag end hanging out.
I picked a couple of those up at last years ice show. I have them attached to my tackle boxes since so small and use them constantly when I retie. I haven’t found a line they don’t cut easily yet.