Been playing this game since 2006, but never had a healing-char. I've tried it briefly a few times, but I thought it was time to make a healing-alt, because it would be really nice with some variety, since I have mostly DPS-chars.
I've reached level 52 through healing dungeons, and I must say that I love it. I play as a Resto Shaman, and healing is really fun. However, this is the first time since I started playing WoW where I truly feel the pain of being a healer. There are smooth runs, but then there are THOSE runs when all the darkness in the world manifests itself into that one bad player, or that bad group.
In some instances I find myself both healing, tanking and kiting mobs. It's not just tanks who can't hold aggro, but DPS:ers who figure "lets pull more because why not, i'm bored", and suddenly you see a hunter rushing out of a room with 3 more packs. It's really baffling.
But anyway, to make a long story short. Healers, I feel you. I love what you do, and oh god my brain hurts sometimes.