I think I've used just about all of the brands/makes out there and settled on Seaguar. A few things to consider. Seaguar actually invented fluorocarbon, so they have the most experience with the material. Some of the brands mentioned dumb down their product because the major retailers force the manufacturer's hand by saying "if you want to sell to us you must sell at this price." So in order to hit those lower price points, the fluorocarbon is not a true, pure fluoro, it's a blend. Which means it will not be as invisible to the fish and may not have the same abrasion resistance.

I use fluoro on everything but dry flies (it can sink the flies). So other than dries, It's used as leader on everything from my 8WT for Steelhead to my wind on leaders on 80 Wides for marlin. On fish with very good eyesight like steelhead and tuna, it makes all the difference. Pure, quality fluoro is very hard for the fish to see, resulting in more bites and the line holds up well, taking more abrasion than mono.

One of the things that we love about using a quality fluoro is that you can step up a bit on leader size and gain a bit more of an advantage. On anything 20lb and lighter I use the Seaguar Grand Max tippet. Over 20lb I use the Seaguar Fluoro Premier. I have done very well by it over and over again. In the Keys a couple months ago, I was getting the bites (permit, tarpon) and the other guy was getting refusals and his flies and presentations were good.