Yes the Hotfix is live (Atonement and MS effects).
I've only done Halfus Heroic in 10s and not 25s. But we don't push halfus below 50% unless Storm, Scion, Time and Whelps are all dead.
I'm with you, I don't understand why so many people risk keeping the drakes alive under 50% unless you run into DPS problems. It is much much riskier to have those drakes alive during the roars then it is to kill them and get closer to the enrage timer.
Well we have 7 healers (including 2 smiters), 4 tanks and managed to kill him in ~5:30; with one healer more we always got into enrage.
We killed whelps, storm, time, but not 4 drakes - So I think our dps just totally sucks :/
Put in a few attempts (about 30 minutes) in last night in 10 man using 3 tanks and 4 heals (one being a smite spamming disc priest), and it was feeling really smooth and easy. Only issues we were having were from missing interrupts during the first tank swap, which we were getting down pretty well toward the end. Whelps were dying around 1 minute in, with the other drakes all sitting between 70-80% health (demo lock + fire mage spreading dots ftw). The way I figure it, if we can down all the drakes by 4 minutes in, we should be able to burn the last 65% of his health in 2 minutes no prob.