As I have said many times this year, I am a big believer in fluorocarbon line (espescially Seaguar). I use it on everything from finesse fishing to worms and even topwaters. One thing I haven't really done is used the heavier stuff (20lb+) to flip and punch with. I was reading Rattletrap Rambling's blog the other day and he made a reference to how J.T. Kenney likes to switch from braid to 25lb fluorocarbon "when there's a really bad cold front or when there's a lot of pressure on the fish. He says the sawing noise from braid can be a detriment and fluorocarbon makes hardly any noise and is also less visible." Makes sense to me.
I just got some 20 and 25 lb test Seaguar InvizX and AbrazX and plan to try it out a few times in the next few months before before my big tournaments start. I want to make sure I'm not breaking fish off in the thick stuff before I use it in a tournament. I really doubt the 25lb will break very easily as my 15lb stuff is really strong. I'll let you know how it works. More bites is always better!