The only time I've ever found it useful is when fighting Atheon, and only then in a very specific scenario. Titan drops a WoL bubble at the back of the room, I go into bubble with Angel of Light on then jump up and aim. This gives me enough time to fire 2 Gjallarhorn rounds before falling back into the bubble, instead of one. Like I said it's a super specific situation, enough so that I might as well call the perk useless.