Don't forget that a small rod can make a big difference. I fished a small stream in Arkansas with a 6ft 3wt and could roll with no problem. I frequently use 7 and 7.5 foot rods under the cypress trees with sidearm casts.

I am a heretic when it comes to leaders. If I am fishing a small stream and need 3 feet of 6x for the drift, I might tie 3.5 feet onto a heavy butt section creating a 6.5 foot leader that casts well enough for the intended purpose.