The more I use "Incoming!" the more I love it. it's amazing for a lot of missions, especially if you're going back to do some of the earlier ones for Master's where Kournan bowmen line up and try to spike you to death, also against areas with a lot of Elementalist mobs. And it's certainly proven very very useful against a certain lategame boss that can deal a massive amount of damage. I can't wait to use it in PvP to counter spike teams.
One elite that I wish I hadn't spend time/money capping was Anthem of Guidance, which I personally think is pretty weak for an elite.