Decreases the cooldown of your Crusader Strike and Divine Storm abilities by 1.5 sec, and allows haste effects to reduce the cooldown of your Avenging Wrath and Guardian of Ancient Kings.
(Since with 3 sec CS, you wouldn't want to chain AW and Zealotry anymore, and haste reducing the cd of optional supplementary abilities instead of our core rotational ability would make more sense and be less punishing because haste isn't the stat we are stacking.)