I usually get 16 min runs in DF as tank or healer. If it's lower it's usually when one or more isn't well geared.

Back to topic, just remembered a Syrcus Tower that I queued for last year. Got ready for the pull, went in, and right during my first combo the entire floor's worth of trash hit me and I didn't get a single heal. Before I got off any cooldowns I was dead on the floor. I didn't even want to off tank the rest of that dungeon. I refused to pull any more encounters because I could not trust the healers. Kept adds off my party and didn't say a word. I won't rage on people who don't do their job but god I wanted to say something.