I prefer the old school system.
A mob lambda = 10% chance to resist stun, 10% chance to resist bleeding etc ...
A boss = 80% chance to resist stun, 75% chance to resist bleeding etc ... And why not 125% fire resistance to make it invulnerable to a school of magic.
Currently, once the armor is destroyed, we can chain endless stun a boss, I find it ridiculous and unreliable.