I use fluorocabon leaders all of the time now when fishing in the bay. I have tried fishing the same baits in the bay with flouro and without and would get bit 2-3 times more on the fluorocarbon. As far a leader length I have found that you can start with a 24-30 inch leader and that should be fine most of the time. When using swim baits and such I go with a 20-24 inch leader just for ease of control when trying to cast accurately. I use the shorter leader for swimbaits because it is a reaction strike that you are getting and there is not much time for the fish to notice line diameter, IMHO. Now when fishing grubs (my love)or worms in the bay the longer leader is required because the bait is worked slowly and the fish have alot more time to notice the line. I also have alot less abrasion problems when using a flouro leader, I think or so it seems to me.
steve