Urgh, my personal experience has led me to loathe a dungeon I once loved.
Levelling WHM (my second class) I decided to only level fron 32 to 35 using Brayflox in order to maximise my chances of getting the full Battlemage set. Not only did I not get any of it due to the place being full of DoM Damage Dealers, its full of over-confident under-able players, who more often than not, also have severe attitude problems.
I always start the dungeon by stating that I like to sleep mobs to reduce my healing load and ask that everyone tries not to wake slept mobs if possible. I also ask the tank to mark mobs as it tends to keep the DDs attacking the right thing and allows me to sleep what I can without wasting time/MP. I find that for a 3-mob group I can sleep 2 before the tank needs healing, at which point I can throw out some DPS and keep an eye on the slept stuff to make sure it stays that way.
However, DDs seem to attack things at random and everyone seems to take offence when I politely ask them to stop waking stuff. I once had a tank respond 'But I can cope with it', to which I replied, 'Yeah, but its mainly to make my life easier'. Poof - gone, rage quit over that, before the 2nd boss too! I started refusing to heal DDs that woke sleeping mobs, thinking it might help them learn to focus on the correct target, sadly, it doesn't seem to work and just makes the whole thing longer, so I've stopped.
Personally, I think this dungeon is a bit of a difficulty spike, and players that have got by so far despite being poor are now running into problems.
Disclaimer: Yes, I've made/make mistakes and am still learning WHM. Yes, I've had fantastic groups where we ran through without a problem. No, I don't think its my lack of ability that's cause these problems, as I'm having very few with Qarn, despite not getting any gear upgraded since I started Brayflox...