seaguar fluorocarbon -- has worked for many years of Salmon / Steelhead fishing always carry a spool of 8, 10, 12 for salmon
and 4,6,8 for steelhead
I have been using the P-Line Fluorocarbon and P-Line floroclear
(Fluorocarbon coated fishing line) and have not had a problem with either of them, actually like P-Line the best--I just purchased P-Line HALO fluorocarbon in 4lb diameter--seems to work well when using nymphs ( all of these are pretty good on a spinning reel too)
I buy the 300 yd spools, it is about the same price as the 50 m or 30 m stuff........not truly TIPPET material, but for nymphs, salmon, steelhead it works and I have not had a problem catching fish with it
for trouties I like Frog Hair I use the 6x and 7x flurocarbon and regular tippet material...............for strictly troutie fishing I buy the 30 m spools ( i usally have 8x through 4x dangling off my vest or chest pack)
it is not in my head that if I don't have flurocarbon I won't catch a fish.....standard tippet works fine.....I like the flurocarbon for tiny midge fishing and really spooky fish
ps...i almost forgot........I have had really bad winter knot results with the berkely vanish........that was many years ago, but I stay away from that stuff