I use braid, braid to leader, mono, and fluorocarbon depending on the gear and technique being used. I would use fluorocarbon more often if I never backlashed, never snagged, it was more available in my area, or I was very wealthy. My problem with Fluorocarbon is if it gets kinked ( from not exercising patience while removing backlashes), or over stressed from pulling on snags it needs to be replaced. It is expensive to replace, so I take a gamble, roll the dice, and sometimes loose my shirt. Knots can be a problem with Fluorocarbon but as of today I believe I don't have a problem with Fluorocarbon knots. It does last far longer than mono if not abused, but I am rough on all my gear, so I only use Fluorocarbon for my T rig and Jig fishing. Fluorocarbon is also less visible than the other options, but for most of my bass fishing, visibility is not a consideration. I currently use 16 pound Sniper. Braid lasts for ever, does not stretch, and combined with different leaders can be used effectively in a variety of situations. Braids down side is because is has very little stretch it is very sensitive when fishing a tight line. The problem is when there is any slack in the line it has zero sensitivity. Many situations when I want a bait to fall naturally I am forced to give a slight amount of slack in the line. This is when the sensitivity advantage of braid is zero. Fluorocarbon is heavy, and sinks making detecting slack line bites possible even with a slight bow in the line. When I am fishing moving baits on a tight line, braid gives me great sensitivity, the problem is I don't need great sensitivity when fishing moving baits. Braid floats so is perfect for topwater, is very strong for it's diameter, making it perfect for punching or flipping heavy cover, and with a variety of leaders is extremely versatile. I currently use 30# or 40# Diawa J Braid.
Mono is a compromise in most applications, but it can be used effectively in any situation. Slack line sensitivity is not as good as Fluorocarbon, but better than braid. It semi floats, so works well for top water, but not as well as braid, It does stretch making hook sets with bottom contact lures more difficult, but far from impossible, and the stretch makes it great for fishing crankbaits. Mono is slightly more visible than Fluorocarbon, but not enough to make a difference in most bass fishing scenarios. Mono is inexpensive, which is a big plus in my book. Mono may be a compromise, but there are many times in life when a good compromise is exactly what is needed. My favorite mono is Maxima Ultra Green, with Big Game a close second.
This is my opinion on lines, and I'm sure others here will rightly disagree with me. I have to stress, this is my current opinion and I reserve my right to completely change my theory's at any time, without past posts being held against me. Weather I use Fluorocarbon or not depends completely on the current condition of my on again off again, love hate relationship with Fluorocarbon.