We managed to kill 25H Twins last night in 15 pulls (woo!), and yeah... Fan was pooping on me with 3 stacks with cd's. I could foresee taking 4 stacks, but I would need to stack at least 2 CD's to live... probably 3 to be safe.
We did just have our Dk tank just pick up all of the beasts of nightmare, since I did more single target dps it helped get Lu'lin around 38-40% hp before the first day phase. A bunch of our wipes were due to her not throwing a second Ice Comet out before doing Nuclear detonation.