It all depends on what you want to do and how you want to fish.

Big flies that kill line speed or teams of flies that require open loops usually do better with heavier lines (9-11 wt), whereas spooky bass on tiny bait in tidal brooks, lighter lines (3-6 wt) come in to play. All of which I cast on the same rod, yes Dudley a 6 wt.

High line speed is as much of a crutch as excess line weight. The key is to learn how to use them both.

As it is with trout fishing the anglers skill is the key to presentation, not just the gear.