So you did exactly what everyone else has been doing, and this is news why? This isn't the "brag about killing Sarth+3" thread.
We did it this past monday. Our Raid Comp.
Feral Druid with Polar Set and topped at around 55K hp
Prot Warrior on The 3 Drakes
DK on the Whelps/Ele's
Healers: Resto Shaman, Pally
DPS: Ele Shaman, Ele Shaman, Boomkin, Shadow Priest, Warlock.
We did 1 full night of attempts, than we got it on the 2nd day, on the 2nd attempt. Healing looked kinda hard at times, but having the DK on whelps prevented the healers from getting hit, and they just spammed away. We did have the 2 Ele's help heal at times, but you gotta. You gotta run with 2.5 healers, because it eliminates the strain, and makes for a much smoother kill.