Seeker, I haven't used Fireline since I have been so pleased with PowerPro. I don't use it for everything, though. I use it for worms, jigs, Carolina rig, and Flipping/Pitching. The pros and cons-
Braid has almost no stretch, which makes it extremely sensitive and makes for a good, solid hookset. It is much stronger than the same diameter mono. The 50 lb braid I use has the same diameter as 12 lb mono. To give you an idea, February last year I pitched a jig over a flooded treetop and set the hook on a 20 lb flathead I never would have pulled through that treetop with mono.
The cons-the no stretch can be a disadvantage with baits with treble hooks-some stretch is good to help keep the hooks for tearing out. It is also more visible than mono, which can be a problem in real clear water.
flourocarbon-low stretch and invisible under water. I never use a flouro leader, but a lot of people do.
Bottom line is it comes down to personal preference-just use what works for you.
I use three lines-braid for the reasons abobe, mono for baits with treble hooks, and flourocarbon for weightless soft plastics like flukes or Tiki Sticks. Hope this helps!
Just read your post again-for the real heavy stuff I use braid for weightless soft plastics in addition to the other applications. sometimes you get in the real thick stuff that would tear up mono or flouro.