22%/8 always deducts at least 8 damage, but possibly more if 22% of the damage is more than 8. 19%/10 always deducts at least 10 damage, but possibly more if 19% of the damage is more than 10. Therefore, 22%/8 armor is equal around 45-50 damage and better at higher damages. You just have to consider how much damage you take from any individual attack at any point. Early on, high thresholds tend to be better because they usually are better against SMG/assault rifle bullets, but even later on, a tacvest with an anti-rifle plate (and the incredible damage threshold it gives) can be better in certain cases. However, higher DR% tends to slowly become better as the game goes on since sniper rifles and strong melee attacks start to become a bigger, as well as more common threat.