Warlocks do pretty well in this fight the improved voidwalkers really are doing quite well at this level and they don't get kicked, though do take damage. Spreading out helps since if you pull aggro you can lay off somewhat (maybe use a sacrifice) and the other locks can finish the fight up.
Hard instance to grind except for horde maybe since you cannot walked out and reset and dying out is a slog. But its some good xp at level.
