Fulling Mill Fluorocarbon is in my opinion a fairly reliable line which I have to say I have had no major problems with. It is cheap and pretty good value compared to most fluorocarbons. The only issues I have with it are that its fairly stiff, and its relatively high diameter for each breaking strain compared to the more exotic lines.
I have spools of this stuff from 10lb down to 4lb and still use it if I am stuck and find its on the whole OK.
In recent years I have found myself using the 4lb variant quite a lot in my stillwater Brown Trout fishing, and have used it on ocassions on rivers too. Reliable and does the job in most circumstances I have no problem, recommending it.
