More importantly, if you have all ranged DPS (or any ranged DPS) you can put them OUTSIDE the room and not get thrown all over by the gravity well. They'll still go in the air but they won't move around, this way when they drop back down they'll all be facing the right direction and you wont have to turn or move them at all.

With my 4 shamans, I drop 4x healing stream during gravity wells to counteract the damage, works well.