Florocarbon?

[BrowningFisherman]

Either way you want to argue it (some fluoros DO absorb water and some do not) fluorocarbon is more invisible under the water and it is because it has the same light refraction as water that it is much harder to be seen by the fish, and to get back to the point of the original post if you are used to using fluorocarbon don't switch to mono because it will affect your fishing, as far a rigging it up on your leader everyone is going to have an opinion and everyone will think theres is better.It is your particular style of casting etc, will determine what is best for you and I don't think any of us can diagnose that over the internet. The line is probably the most important piece because at the end of the day it is what gets the fish in, if you go cheap or you switch to mono you will either see less fish on the end or lose so many flies that the switch won't be worth it.