I use nothing but 2# test Fireline Crystal on several of my crappie rigs. Have been using this line since it's conception when all that was available was the smoke color. Just put it on my new Diawa Presso 7'6" UL rig dressed with a #20 series President (and the 2# test Crystal of course). Works perfectly all the time for me. I am mainly single pole casting and/or side pulling a couple of rods at a time. I also use a 4' fluorocarbon leader for the increased abrasion resistance. I connect the lines using the Alberto knot, which I've been using for almost a decade now.

This line and rigging as performed flawlessly for me, while affording me a greater degree of sensitivity than mono type lines. But what it all boils down to is what gives you the highest confidence and success in your particular fishing situation. And a lot of what you need to use depends on the way you fish and type of water/cover you have to deal with. JMO.