O.L. you always have my attention, and Dr. Ashby, I have learned much from you too! I shoot 5 3/4 inch feathers because they look good, are traditional.
Tuning my arrows has not been a problem for ten years, I have used the bare shaft method, and the Adcock method. I have used the extreme FOC long before I knew what you called it, because it worked.
Having shot competitively with compounds for several years, I have understood the advantages of using small fletching. When I went to the woods, it was always five inch feathers.
Most of my hunting consist of shots in the 15 to 25 yard range. I have taken game at 35 yards to 40 with my traditional gear. I have eliminated the noise problem, as much as possible by taking just a little off the height of my big feathers, with my burner.
I don't think my feathers are a handicap, and I regularly shoot my bare shafts at twenty to thirty yards grouping with the feathered shafts.
I agree, match your equipment, tune the son-of-a-gun to the point it is supposed to be, not just close enough. Shoot whatever length feather you want, but as stated above, do it for the right reason. There is no room for short cuts in bowhunting, modern or otherwise. I like big feathers, bright crowns of 11 1/2 inches, colorful crest, and heavy shafts 11 - 12 grains per pound, with a lot of FOC. It works, but may not be your way.
I learned this by listening, and making a bunch of mistakes along the way. Let my mistakes be a sign post, someething to be avoided.