I need to add Avolanty and soccerking to my friends list, will probably do so tonight.
So I finally had time to screw around with my Ice Breaker and I really like it (plus it sounds so freaking awesome). Regen time on the ammo is freaking fast too, fully understand why it's such a sought after weapon. Fully intend on using it to it's fullest (but I still need to get a better main hand, I like the hand cannon but I just feel so underpowered with it) and luckily with it I now have a sniper rifle of all damage types so I'm covered.
Ward of Dawn is probably the most effective for high level situations as Sunsinger really doesn't bring much the the plate other then the solar damage and their ability to self res (plus Song of Flame does decrease cooldowns for all fire team members when it's activated but it takes away the self res ability). I've looked at the tree fully as I'm leveling my Warlock as a sunsinger but really it's not that great (I do love their grenade types though). Honestly a Voidwalker is better to bring along for all high level encounters.