21str/Xagi
56 hp, 65 armor vs 70 hp 57 armor. On average that's about 3 damage per hit for cut weapons, less for pierce or blunt (because the additional armor counts for less).
I can understand the argument here, that it seems like this is a little too similar, but you're still oversimplifying. That 7 additional weight causes you to lose far more wpf than what you gain by the mere 3 agility, likely even with the additional 1 WM you could get if you spent an 8th skill point.
On the other hand, you could simply leave your armor unchanged, which is what most people do, and take the additional athletics for what it is (the speed increase). If you're doing that though, you can't be tempted to talk about athletics increases as though the effectiveness gains remain the same at all amounts/weights, which is what most people have done, thus far. As athletics increases, so too do the penalties on movement from weight. Meaning that you gain more effective athletics points at lower values than at higher ones.
Second, if you're already running faster than 95% of the playerbase, one additional athletics point so that you can run faster than 98%, isn't even worth talking about, that's about as minor as it gets. Furthermore, when fighting in groups or closed in areas, you're not even capable of utilizing any gains you might have from athletics. What's more, if your weapon is significantly shorter (20cm+) than your opponents, they're able to minimize any effects one would normally gain from athletics.