Quote Originally Posted by Fendred View Post
If the boss is giving openings for a swap, sure. I don't see the point of doing it otherwise. I've seen warriors swapping stances during boss casts that are under 10 sec and that is what fueled my comment. If a tank is taking regular direct hits from a boss he should be in tank stance.
That's because you don't need any more mitigation than what you have without tank stance, outside of very specific scenarios, and aggro is super easy to manage in this game without needing to use aggro combo. A WAR opens a boss fight in defiance+unchained, and four GCDs later (tomahawk > heavy > maim > eye) can switch to deliverance and basically stay in that stance for the whole fight. You might want to switch back to tank stance for things like picking up adds, or when you need to heal yourself for some reason (usually you have a dead healer or someone screwed up a mechanic), but outside of that you want to be in dps stance as much as you can.

For anything that isn't ultimate/savage/extreme content, the extra dps usually isn't crucial, often casual players wouldn't even notice a tank pushing his dps in a dungeon.
Even some extreme trials don't actually need the tank to do much damage (Lakshmi for example) provided the dps players have decent gear. But for anything that is endgame content, the less you push your dps, the worse it is for your team. Fights like regular kefka in O8S simply wouldn't be clearable without the tanks pushing their damage as far as they can. The added dps from tanks lets you push through phases of the fight faster, which in a way, mitigates damage because the longer each phase lasts, the more damage you take.

Of course you still have to do the basic tank things you're expected to do (Hold aggro, mitigate properly through the use of cooldowns, proper boss positioning), but your raid team needs you to do damage for the sake of everyone there, and because the basic tank responsibilities are very easy to do to begin with. Holding aggro is a joke, cooldown and mitigation can be planned for the entire fight, and so can positioning be.