There are only two occasions where I DON'T use fluorocarbon: Fishing jigs, plastics and frogs in heavy weeds (I use braid here) and when throwing any floating topwater, like a spook (I use mono here). Fluorocarbon is nearly invisable underwater, and it sinks vs. Mono, which floats, which is why I use mono for topwaters. However, I find that flourocarbon excels when throwing crankbaits and jerkbaits because it helps them get down a little deeper and stay deeper. It also gets the nod when I am fishing clear water, or useing a general finesse technique, like drop-shotting. However, it is NOT without its flaws. Fluoro frays rather easily, and is notorious for gaining weak points throughout a days fishing, resulting in lost lures or even fish. You should retie often. In conclusion, EXPARIMENT. Throw a crankbait on 12 lb mono, then the same lure on 12 lb fluoro, and see what you like better! TIGHT LINES!