As DRKs we don't get nifty things like block or increased health and healing potency via Defiance (not to mention parry is unreliable as hell) so even though we are popping CDs, it feels like we are taking a good chunk of damage. I don't feel its overkill to help healers out on any healing intensive pull by using this method. I don't end up having any mana issues so personally there isn't any reason for me not to.
