I agree that we shouldn't overestimate the strength of a build just because a lot of people play it. But it also is a strong indicator of what people value. People REALLY value speed. And to a certain degree I understand why. I myself have many times said something to the effect of "Speed and stealth are the two most powerful things you can have in an open world setting."
The two things those mechanics have in common is the ability to force fights you do want, and avoid fights you don't. Like, I don't care how strong Teknique's Ohg build is once I have enough of a speed advantage (theoretically speaking obviously as we aren't enemies in-game). Because I'm only going to engage it if he's outnumbered. Sure he can beat me 100% of the time in 1v1s but if I can beat him in a 2v1 and break away easily if things aren't going my way, I'm cool with that. I would never allow him to 1v1 when the stakes are high because I have the choice not to, where he would have no option to escape me when I want to press a fight. That's a huge reason Harbingers is going to be a cav only guild once mounted melee and mount armor make it in.
A 1.7% speed advantage with no stam advantage is so small that a Kallard who is slightly better at picking paths could beat a Khurite in a footrace on anything but perfectly flat terrain. And I don't mean world-class racer Kallard vs. newb Khurite, I mean any Kallard who is slightly better. Meanwhile the Khurite has to be moderately better to consistently overcome the 12% advantage a Kallard has in a head-to-head fight. Turn that speed advantage into a real/strong advantage though, and it suddenly makes sense why everyone wants to play Khurite.
I like the idea of Alvarin getting major speed to weigh out all the downsides they have and make them the ultimate diver/flanker/harasser build for foot-fighters. I really don't like the idea of speed being much bigger of a factor sub-Alvarin when we know, real or perceived advantage it will absolutely kill build diversity.