Well I have queued as a tank, healer and dps. So far here is my experience on both Normal/heroic in LFD.

Tank:

Well already explained that I have completed far less in pugs than I would want to. Too many people dpsing the wrong targets, breaking CCs (and sometimes breaking their own CC...). Queues are almost instant yes but so far 70% of my lfd has been half finished dungeon or in front of the first boss, followed by 1 wipe and everyone leaves. (Typical Wotlk genre people)

Healer:

Everything is quite hard. I am better geared now since I was fortunate with some loots from normal dungeons. It doesn't help when people doesn't use CC, and also doesn't help when they don't focus on the same target (longer time, more stress on my mana). Since I don't heal much in comparison to their ginormous health pool, struggling on spells to use on aoe fights.

DPS.

Now this is the fun part. I successfully "Joined" about 7 of them with 30-40min queue. But I never actually managed to "do" the dungeon itself cause the tank instant leaves when he see "Stonecore Heroic" or "Shadowfang Keep Heroic". Yes 7 out of 7 I had the group disband before I do anything. Joined as Destro warlock btw, so I could bring some decent CCs on the table, and interrupts using the felhunter.


All in all, cataclysm has created another type of group. "Guild run Only" group, which doesn't help the LFD system but I cannot blame them. Although I do find quite annoying people saying things are easy mode already. Well of course its easy mode if you are playing with 4 other people with brains. Doesn't take 3 expansions to understand that playing with people who know how to play makes things easier.