We got to 4% with the standard setup - 2 tanks, 3 healers, 5 DPS. We then decided to swap a healer for a DPS (healer's offspec) and it went so much smoother. Sure, we had a few wipes this way with some random mistakes, but after swapping to this we downed it on like the fourth try. In P2 we went for three add waves with dps spread on tentacles for interrupts, then just zerg Cho'gall. We killed it with like six people alive.
I'd say you get it with 6 DPS, and the easiest way to do this is to have good and/or geared healers that can duo it. We were kinda strapped for DPS/healing/tank suvivability since half the loot we got so far have been disenchanted, so if your group has close to full epic it should be very smooth.
I wish we could 2 heal it, our three healers are having a hell of a time with the huge tank/raid damage going out.
We did it with this setup-
Healers:
Holy Paladin
Holy Priest
Resto Druid
DPS:
1 Survival Hunter
1 Frost DK
1 Feral Druid
1 Elemental Shaman
1 Destro Warlock
Tanks:
Prot Paladin
Blood Death Knight
Personally from my perspective as a Holy Paladin, I think the key thing is making sure you have enough DPS on the adds. If you can get your group to prioritize fast swapping to killing the small corrupted adds that spawn without taking any damage from them, your corruption won't fill up quick enough to slow you down in the 3rd phase. Then, you really take a lot of difficulty off your shoulders. Of course managing your corruption is a big one too. Try to have good situational awareness and dodge the shadowcrashs and stuff.
I read this post and wanted to lend the OP my insight so I made an account and just registered so I am not allowed to post videos or links but if you private message me I'd be happy to show you a video from my perspective.
I hope this helps!
Stack up behind Cho'gall during P1 and use a Destro Lock to Shadowfury Conversion.
If you're a warrior tank this might be helpful. It's our warrior tank's PoV: (just mute it if you don't like the music)
Remember to HD it (1080p available)
Last edited by tet; 2011-02-20 at 09:02 AM.