I would say Gladiator Suite for warlock. I know charts aren't everything, but I've used it on my affliction lock who is not quite combatant's geared and I've topped the damage chart before. The CR is amazing at keeping all dots up on everybody within range.
I am a warlock and I can tell you that my personal experience is that Gladiator Suite although being the best for Arena, Mills beats it in RBGs. Mills seems to handle large group pvp better than Gladitor Suite which does awesome in 3's and 2's.