B23,
Let me assure you that my post was not directed at you. I was just speaking from my point of view - and I probably should have put an "IMO" somewhere in the body of my comments. Others say "mileage may vary".
I would not dispute your findings for a minute. I know some bench rest shooters that simply will not use Vihta Vouri powders at matches here in Phoenix, but will use them in matches in Raton, NM. The subtle differences in accuracy warrant it in their circumstances. But given the fact that I am not in the same league as them, I don't worry about changing powders or loads when I hunt in different states or even at different altitudes. When hunting, "close is good enough" seems to hold true for me.
I am not a good enough driver with a rifle to a point where a 3% increase in velocity will make any difference in my abilities. For others - they may appreciate it and feel it gives them the "edge" (pardon the pun - I couldn't help myself).
I currently shoot a 277 AM (338 Lapua necked down to .277). When the barrel burns out, I am looking at going with the 338 Lapua because of my current diameter bolt face. As long as I am looking to make the change, I also am looking at the 338 Norma Mag (same bolt face). I am also considering the 338 Edge, along with the 338 RUM and other wildcat 338's. In the end, they all offer great performance. Some will give me a boost of 100-200 fps over the Lapua and Norma Mag. But honestly, for me, I don't think I would be able to tell much of a difference until I got beyond 1200 yds or so in wind deflection with the 300 SMK. Because I shoot so little beyond that, others factors come into play as being more important to me - such as quality of brass, saving $$ by not having to retool bolt head or buy new custom dies, etc.
Many of us have spent big bucks on custom rigs that quite frankly did not quite measure up to expectations in the accuracy department. Bench rest shooters know this for a fact. Some new custome barrels just won't shoot to fulfill their needs. When they get one that doesn't, they just change it out again. Given the fact that accuracy is not an absolute given - even in custom barrels and rifles - I personally would never give up a known "shooter" for a 3% increse in velocity. What would it take? Maybe 250-300 fps more? Perhaps. But that is just me. Mileage may vary for others.