said by Cptbeatstix:
-Double Time removes Charge's cooldown, instead making operate on a charge system. Maximum of 2 charges before the cooldown is started. Each Charge has a 20 sec cooldown and only 1 generates 2 rage. So if you charge twice in a row, 40 second CD.
Partially true. It's a 40 second CD to get all your 2 charges back. You can actually charge again every 20 seconds after you use your initial 2 charges, as if it's been reverted to an untalented ability. I find double time to be very situational, mostly in PvP where it can have some great utility upon opening an attack, especially in 2v2 arenas or against blink/roll/port and even pushback classes.