I finished heroic Halls of Reflection for the first time yesterday night and it all started with a couple guildies an myself looking to run the Forge of Souls and Pit of Sauron.
I was on my druid and expecting to tank, but it turned out our healer was saved and forgot so he flipped to his tank and I was going to heal. We usually try to keep the healing and tanking roles withing the guild so we are guaranteed some base level of competency.
Of course our tank who usually prefers to queue as DPS didn't have tank checked when I queued and lucky us we had a group like two seconds later with a pally tank and a rogue that LFG picked out for us.
We plowed through the Forge of Souls my only complaint being that the one time I hung back to loot the tank ran off ahead to pull. I was having some bag issues and deciding what to pitch. Anywho a little cat dash and I was there to heal none the wiser.
Things went so well that we all agreed to go right on to the Pit of Sauron and again we charged through the place. Another loot related cat dash was my only concern, but it turned out fine. So obviously we unanimously decided to proceed to Halls of Reflection.
This is where I thought to myself, if we had gone with our original plan of keeping the tanking in the guild rather than PUG a tank by chance we probably would never of attempted Halls of Reflection.
Notably because our tank would of been saved and potentially flipped to heals instead of flipping from DPS to DPS. Keeping our tank tanking and me healing preserved that momentum we had from the previous two instances. We knew what to expect from each other and it all clicked.
It was a good thing I was healing two instances prior because I needed that warm up. I am a feral druid first and foremost and do pretty much all my healing on my shaman. Had I started cold turkey I doubt I would of done as well. Plus I had practice before that even healing Arathi Basin as a gnome for the holiday achievement (Blizzard hates feral druids by forcing them to heal for that particular achievement). Nothing gets you smacking healing buttons like a good bout of PVP.
So the end of Phase 5 and the first "mini" boss I get feared twice in a row, my hots fall off and boom the rogue and I die, but the boss goes down as he was at like 2%. Couple rezzes and we get through the first half of the instance without further incident.
We wiped once running away from Arthas due to melee placement, cleaves and abomination juices. Second time through was much smoother aside from the last group at the very end of the run. It was hairy (mostly due to casters in the back pelting me as I had healing aggro), but no one died. It was better I have a little healing aggro to heal through than for melee to get two shotted getting stuck in the wrong position. I can respect being a tank most the time that keeping aggro on casters who hang back while keeping ahead of Arthas is not an easy task.
We won and it was time for bed. Ironic that I had to heal though, I was looking forward to trying out my recently acquired four piece tier 9 bonus on my tanking set. The irony being that I unchecked tank earlier to run the heroic random. That PUGed tank turned out to be quite alright as well.
So the moral of the story is that it might be better to queue for the role you want to play rather than queue for the role that you think would be best for the group.