Fully or moderately geared you can average a 1000-1100 (lil more or less depending on the class) second wind which is a substantial help in a raid not to mention if you mantra yourself and get a crit it wards off death should a healer be late getting to you or has to prioritize the tank in that situation until they can get to a hurting dps. Any bit that keeps you away from death is always a help to the raid.
