I liked 4# test line because it casts further, and gives better lure action. However, I just lost three monster Smallmouths today, no contest, just snap! Yes my drag was set to give line, but when a big fish heads for a downed tree, you have to be able to turn it. The untra light with 4# test was fun for catching the little guys, but when a trophy breaks you off, it ain't worth it. I'm thinking 8#, but hate to lose the casting distance with small lures.