I have only had one problem with Siege, it was from an old run, that sat on the shelf for over a year. Otherwise it is some of the best leader material I have ever used. I ran it as a mainline for a while, but for it is better suited as a leader material...About your breakage. It has an abrasion resistant coating on the line to help negate normal wear on your line, but it also requires you to double seat your knots. Otherwise it slips on itself quite easily. It i hard to tell whe mainline breaks, but I am almost sure it just slipped at the swivel. A slip from a knot will leave you with a little "pig tail" while a real "break," or line failure will be much more clean and uniform, not all wound up. Which did you have after the break?