I'm not sure if it's class or just ARR dungeons but if there was an ARR roulette, I'd run it every day on a tank class. I don't find it's until after ARR that floor disco really starts to go next level and mobs will begin to heat up on the healer enough that a tank needs to double down. Leveling roulette almost does it but you still have a chance at some of the hoop jumping fests l just don't feel good about in a DF run on healer or tank.