Having a 50 WHM I can see why this ability is nice. But it is often used improperly. What I see is WHM's most but not all will use this ability as a dps move. But what it does is slow down the overall group dps. If you want to fluid aura then sleep by all means but wait until after the first flash or overpower. But if you want to dps and use it. Then you are not only screwing over the tank and his threat generation but any melee dps who you just knocked out of their reach and potentially messed with their rotation.

Thank you for all the heals.