Definately not junk, just as with any other line it has its place. IMHO it is not as abrasion resistant as manufacturers want you to believe. It does have good knot strength and is very strong. Almost invisible (obvious advantage in clear water) and it will sink....not float (get an extra foot or so on a crankbait, definately a no no for topwater). I have found that if the line gets nicked and/or kinked (like after a backlash) the line gets pretty weak. Retie often and check your line often. Since it has less stretch than mono it is more sensitive, but you can exceed the break strength on a hookset....TRUST ME! Did it yesterday in a tournament and it cost me big fish and the 45 minitues it took to coax it into biting....
As far as brands...I assume most can guess the line I use....Bass Pro Shops XPS Signature Series Flourocarbon. It works for Kevin Vandam, and it certainly works for me, just not ALL the time. I have used Berkley Vanish, not real happy with the stuff. I have heard really good things about Seagar, but it is expensive.
Hope that helps.
Mini