In my opinion, the limiting factor is almost always the person holding the rod.
I wish I would have said that.
Like some others have said, I like to use a rod for the conditions I’m fishing. I can land fairly large trout quickly enough on a 4 wt when light leaders and small flies are needed. If I’m tossing heavy flies, wght’d leaders, etc. then a 5 or 6 wt does a better job for me.
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