What is up with these new Warlock Sets? Chance on hit to cause the attacker to flee in terror for 2 seconds? OUCH! Talk about Instance Insanity! What were they thinking. No Warlock is going to be able to wear their set into an instance without a "chance on hit" to agro the whole instance. This is why Priests learn early not to fear in an instance. At least they have control over that. Blizzard should at least give us the option of turning that off and on.
Death coil gives a 3 sec fear effect and I use it when all other means of sluffing off aggro fail, or there just isnt a tank thinking about me at the moment. In all the times I have used death coil for the 3 sec fear in instances it as never aggroed another group.
I love the new set, because it will do what I do out of instinct on its own, and if you are clever, 2 seconds turns into 4, and in 4 seconds a lot of things can happen.