I don't know what gave me a bigger boner: the armor localization in that video, or the fact that Triumph (who is well aware of my tank obsession) posted it
Guys. I've always wanted something like this. While I love finding great defensive/armor items, there's always a bit of a disappointment level when you rush into battle the next time, expecting to take significantly less damage, and realize the difference isn't too big (fucking RNG). Being able to specifically customize your defense would no doubt allow you to see mitigation increases more easily.
GUYS. Imagine a high level dungeon that includes mobs that attack specific parts of your body. So like, snake or eels that mainly target your feet/legs, or little monkey things that attack your torso, or flying demons that go straight for your head. That could be the ultimate gear check. FUCK.
Path of Exile does this with resistances (fire, lightning, chaos, etc) as does D3, and I always loved when I could stand in aoe dmg and barely lose health due to my resists being so high. But having that concept applied to every armor slot would make me bust multiple nuts.