For the last few years I have changed how much tippet I tie on my leader. I usually have a 9ft 3x leader on and then tie on anywhere from 6 to 8ft of tippet and the diameter depends on situation. The main reason I started to switch years ago was I felt I could present a much better cast to a trout using a longer tippet. I have come up with a few reasons why I think it is better and also a few things why it might be a bit difficult to transition to a longer tippet setup.
The most obvious reason is that you have more leader/tippet between your fly line and your fly. When dry fly fishing and you ever need to line a fish with a cast this will help getting the fly above the fish giving your fly more time floating. I believe with a longer float you can present your fly better. Now I know this is not always the case but in most situations it is benefit. With this setup you are able to present a softer landing with your flies even with heavier flies. Trying to land your flies softer also depends on some casting techniques. Now for when you are nymph fishing, you have a great range of distance for changing the depth of your fly. I can’t tell you how many times I have changed the depth of my fly drastically and having the longer tippet I didn’t have to tie on new tippet. One river that I think it is a huge benefit is when floating the South Fork of the Snake River below Palisades Reservoir. There are times during that float where you have to use heavy flies and get it down at least 10 to 12 feet then fish skinny water with a totally different approach with different flies.
For dry flying using the longer tippet will help with casting over multiple surface currents. I have been able to land a fly and give it a longer natural drift. The reason for this is you can land your fly and tippet with more slack so when a current grabs a part of your line the line closer to your fly has more time to sit in the spot you want it.
Now some of the issues you will see when using this technique are with windy conditions it will more difficult to get the cast you want. Until you are comfortable with longer tippet you will experience an increase in knots and tangles in your line during casting. One other thing is that you will probably go through your tippet quicker and have to replenish your supply more often.
If you don’t incorporate this technique now then give it shot. This technique isn’t for everyone but if you try it and it works for you then I promise you will love doing this.