Quote Originally Posted by MagiusNecros View Post
More like they all need time. Whether it be GCD locks, recast times, etc. PLD/DRK use up resources to make an immediate change and are on GCD while Warrior sacrifices nothing but 10 seconds until they can revert into a different stance. And technically they could run a 20 second pseudo Defiance mode in Deliverance through Thrill of Battle and Convalescence.
but the entire point is, as a pld or drk, you gain an immediate effect of 20% badass, where you as a warrior gain absolutely nothing unless you got 5 stacks ready or your next heal. pld and drk work on a matter "ok, it's done" and war is "one moment please"

and as the topic is about the reason for the cost of changing stances, that is exactly why, pld and drk gain so much more the moment they hit that button, where as warrior doesn't gain a nugget of anything until he or his healer does something about it.