I think it makes alot of difference, a fishing buddy and I was at Kentucky Lake we did some testing with fluorocarbon, he was using fluoro and I was using P-line CXX moss green and he was getting 5 to 1, if not more than that, the bites I was getting, you can't see the P-line in the water but the fish can. So if it not off colored water or fishing in grass I would use a leader.

Gary