Ward of Dawn has not so much utility anymore for PvE and PvP than before. So, since it has the Overshield now instead of Weapons of Light, I suggest adding -blam!- buff of Destabilizing Rounds as well to it. As long as you stay in the outer ring of the bubble or inside, the timer for those Rounds doesn't count down. But as soon as you leave the circle, it counts down. 5s I say because of PvP, because in PvE you can just stay in your bubble anyways. Also, it encourages people to fight around the bubble, not grab a buff then run around over the entire map killing stuff in PvP.