Re: one wt over another
My feeling on this is that the number the manufacturer puts on the rod is a suggestion. I wouldn't ever buy a flyrod (especially at the upper end) with just the reputation alone or a suggestion from another person without trying it first and this limits you to buying rods from only the corner store that will let you try the rod. I'll try a range of lines on either side of the manufacturers suggested line weight and see how "my casting style" fits that particular rod with different lines.
I view a particular rod as having a given power(0-14) and a given action (tip action to parabolic). the tip action rod would need a short casting stroke and powerful and agressive power application while the other end, a longer stroke and slower application of power. There is overlapping of these factors when you change lines. The tip action rod will bend more with a heavier line and a slower rod will sharpen up a little with a lighter line.
In other words Joni with a lot of casting experience and a smaller frame might need a 4 on a particular rod and a new inefficient caster weighing 250# might need a 5 just because of the way the rod is loaded.
I feel that a rod is going to have a "sweet spot" with a particular line with a particular caster's style, efficiency ,body size and casting conditions
All these factors will determine the line weight of a rod. The taper of the line can subtly change the performance to fine tune your rod to the conditions and style.
my motto ---TRY IT BEFORE YOU BUY IT
"something is happening here but i dont know what it is"---dylan