Homer -
I believe that Seaguar is one of the original lines from Japan and remians a standard . I have tried a number of brands and found that many of the newer "brands" had no way near the "shelf life" - that is like mono as they aged they lost their strength (both tensile and knot).

The general "toughness" of fluorocarbon leads to my major concern with its use. It is inert as heck and lasts essentially forever. This possible long term pollution factor goes against my "green" nature and as a result I have fallen back to old reliable - Maxima Green for the major of my anadromous fishing and Orvis super fine mono for trout tippets.

Happy Holidays and may the New Year bring you tight lines
S malma