As Lyllea (my disc priest) continues to level and run dungeons (Nexus, Mechanar, and Botanica last night), I've really noticed a massive mindset difference.
It's easy to figure out whether you're a decent dps or not. Are you winning the Omen game (aka pulling threat off the tank)? Are you killing the things that are supposed to die in the marked order? Are you staying out of the bad stuff on the floor? Are you doing decently on recount? If the answer to the first one is no, or yes with the immediate reaction of an aggro dump or bringing the wayward mob back to the tank (for those times when your aggro dump is on cooldown), and the answer to the other three is yes, then congrats, you're a decent dps.
Now, are you a decent healer? This question's much harder to answer. Can you keep the tank alive? But is he appropriately geared and speced? Because if he isn't, well, then the best healer in the world's going to have some issues keeping him alive. And guess what, if he dies, then it's seen as your fault, even if his defense is so low that the boss one-shot him. Now, it is not your fault. Tanks range from the frighteningly idiotic to the inexperienced to the awesome and you're going to run into and possibly attempt to run a dungeon with all of them.
And then there's the rest of the group. Are the dps dying frequently? Are they pulling off the tank? Are they all in cloth and really squishy and gorram it I do not have enough heals to keep all these idiots alive? Then you look above and see that winning the Omen game and not doing anything about it makes them bad dps (or there's an inexperienced tank and if that's the case, the mobs are probably trying to eat you too). And bad dps go lower on the healing list then good dps (who are lower still than the tank). Now that probably won't stop you from going "Frack!" (or the non-work safe curse of your choice) and it probably won't stop them from blaming you, but at least you know why they died (and can stick them on the No Heals list (aka the Ignore List) should you wish to).
What this all amounts to (for me anyway) is that I feel like a good healer after a good PUG and a bad healer after a bad one. Now, I have my healing flaws. It took me too long to figure out where the heck Greater Heal was (apparently I don't have it keybound in Vuhdo and I need to figure out how to keybind to my 4th and 5th mice buttons) and I still don't know all my keybindings. Levitate does not substitute for Circle of Mending. Though it was kind of funny to see the floating dps just before he died. And don't even get me started on Dispel Magic and Abolish Disease and when each one is required. I should figure out what Vuhdo's trying to tell me with the changing box colors, I really should, but in the middle of a battle it's just easier to hit both and see if that fixes it. And if neither one does, I shield them. Because PW:S fixes everything. Except death, sadly.
I'm attempting to cultivate a "Any PUG I learn something from is a good PUG" attitude, and apparently I don't suck as a healer, but when the only real feedback I get is from my fellow PUGers, it's a bit of an ego rollercoaster. But in the end, the lasers make it all worthwhile. Yes, I can heal you with LASERS! It's awesome.