Quote Originally Posted by SwordCoheir View Post
By that logic though, you've cut the usefulness of parry by half if not more depending on the instance. Even if you negotiate instances based on the types of attacks enemies use, the slower or the more magical the attacks are the more significantly blocking/parrying is crippled, and it simply won't measure up to DPS secondary stats (save for skill speed maybe) when capped accuracy removes the only factor that hurts your hate/dps "missing".
Of the bosses that actually pose a threat to the tank (turn ls 5, 6, 8, etc), they attack either exclusively with massive attacks that you can mitigate, or almost exclusively.

Also, I think you underestimate the value of mitigating big slow attacks. An aa that drops you to 5k instead of 3k gives healers a gcd to use on the party rather than you. Anything you can do to give the healers more time (as this, and not mana, is the real gate on healing output) is much more important than saving one gcd.