I think it's more useful than just advertising. If I already have a fast action rod, I have a pretty decent idea of what an extra fast in the same line up will be like without even trying it. This is where there's value with sticking with a brand or even a line within that brand you like. I mean, it's better than than ratings like rugged, elegant, smooth, stiff, etc. At least using relative speed gets you in the ball park. But yes, I agree - one company's fast may be another's mod-fast.