Rekilled it yesterday because of lack of healers for empress, first time since mage ROF nerf (didn't want to waste progress time on it) - we just soaked every wave with 2x hunters rotating, and dps'd down the sparks that got away from us (they can be slowed and do not have alot of HP, so a little focused burst makes them go down very fast). Tactic started out with us aoeing them down and hunters soaking stray ones that got out of the aoe, but people ended up relying on us to soak most anyway by the end of the evening, so became soak>dps them.
You need to jump to get into them, basicly - thats all there is to it.