Melee heavy groups it can be nice (Invigorate not being enough for sustained AoE) And it only reduces damage by 15% from the descriptions.

The term I always head was "Dps ia a group effort, not any one person's" it's crappy to lose that damage (Foes by all means if you have a blm/smn) but when there's nothing except You, a War (Probably not a Drk/Pld, they don't really AoE with TP anyhow) and a Drg/Mnk/Nin, whatever the case, all starved for TP and mobs all at like 80% hp, it will keep damage rolling, if at a small cost to you personal dps.