I'd like to talk about all the "pre-emptive move" people talk about...
I know the fight, I know the skill rotation, I have a paper in front of me and a macro to help me if necessary. But once every minute, I have lag spike and I need to move constantly for 2 to 3s to be sure not to get hit by plumes. Unfortunatelly, I'm a healer and if I move for this long, I'll be alive for sure but the tank may die because of me being late for healing...
I'm far from being the best healer, but lag IS too much punishing in this fight and that is even worst for healer...
DPS (especially bard) have it easy in this fight because they can pospone their attack to dodge plume as much as they want. The true hard step for them is the Heart phase.