Originally Posted by
jontaxe
No. Just. No. Everything in this post is wrong. First and foremost a 1s LB means elemental mastery is now totally wasted. Congrats.
Once LvB (and GCD) get below 1s, haste on that is wasted. Second, haste effects like elemental mastery, troll zerk, hyperspeeds and bloodlust are best popped all at once. When you can't pop them all at once because of haste that haste is suboptimal. Lastly, lavasurge scales atrociously bad with haste, so speeding up flame shock for that isn't a reason in haste's favor.
Per item budget, haste is either a wash or slightly better than mastery in theory. In reality, at current end game haste levels with LvB being under the GCD and just about everything being under GCD under BL and stacked haste effects you are most likely better reforging haste to mastery.
Stay tuned for level 85 or for the EJ kids to do more detailed math.