I have been levelling a Priest recently and have moved on to the Cata Dungeons last night. I've never had much problem along the way healing dungeons. Priest Healing is a ton of fun compared to Paladin Heals. I am having a blast. Every other time I get a tank that tries to push me to the limit I know I can keep up and still pull decent DPS with Atonement.
However, I've been having a hard time with Rapture. I'm not sure I'm using it at the right time. I didn't really feel it was a problem during TBC and WTLK cause my Shields stayed up longer than the mobs for the most part.
RAPTURE "When your Power Word: Shield is completely absorbed or dispelled you are instantly energized with 7% of your total mana. This effect can only occur once every 12 sec."
So that is the tool tip. Now what I would like to know is, how should I go about it? Should I be throwing PW:S every 12 secs? or Can I throw up a few? And What exactly does absorbed refer to? Since they've lowered the duration of our PW:S from 30 secs to 15 secs its gotten even more confusing for me? I'm assuming it doesn't mean till the Shield wears off?