To GC From a healer of 4 years

When mana isn't particularly limited in an encounter, then the main way we have to challenge your group is by making you global cooldown limited on an encounter. Basically if you ever fail to cast a spell every cooldown, your target may die because incoming damage is so huge.

While that might feel very challenging, it also works against some of how we want encounters to play. You can't worry about things like mana, movement, healer coordination or overhealing when missing even a single GCD results in a wipe. This does not mean we want healing to be slow and boring. We do want players to make interesting decisions when they are playing, and we fear spamming your most powerful heal every GCD and never stopping isn't really a decision. In fact it feels more like a macro. :) So we make the risk of that behavior to be that you run out of mana.

(I'm describing a pretty extreme case too, like trying a new boss for the first time when you might be a little undergeared.)

Another way we could have approached the problem would have been to greatly increase the health of every player and then also increased the damage done by the boss. That way you wouldn't be healing a tank for 25 or even 50% on every big heal. When someone got knocked down low, you would have to cast a few heals to get them up again and the focus would be more on who to heal rather than making sure you don't ever miss a heal.

Q u o t e:
Downranking made mana completely and utterly a moot point. Healing in sunwell was a terrible exercise in spamming. It was, for the most part, thoughtless beyond figuring out which heal you could spam forever. That's not to say the encounters were bad, some were truly great, I'd argue that the healing wasn't interesting in the least though.

I actually like the nerfs to mana regen and to be honest I wish they had gone a little bit further. What I would have liked to see in addition to those nerfs though, was a way for my class to actually make a decision when it came to what heal to use. Right now it's almost always a simple priority system based on who my target is, I'm pretty sure that I could reduce every decision I make in terms of spell selection to a macro.

Ideally I think all classes should have heals that are small and efficient and spells that have serious throughput at the cost of a serious loss in efficiency. That makes your healing choices much more interesting, and even better makes your healing choices and assignments in a raid be something more than pallies on tanks, shamans on raids, druids and priests fill in the gaps.

Quoting Pyxis here, because I agree with an awful lot of that.

Q u o t e:
You're suggesting that these were the only two options to make healing harder/interesting. We've already discussed alternative options to this in other threads. The solution to your perceived problem is not as binary as you just suggested.

Well, I was really just talking about how to keep healers from being GCD locked in challenging content. I agree there are a lot of ideas to make healing more fun or interesting and we need to start experimenting with some.

As to why we didn't implement the "big health" solution, it was just the scope of the change. It's not as simple as just doubling everything. Once tanks don't really fear being killed by a boss in a few swings, it becomes a lot harder to keep the fight challenging. But it is probably something we will look at seriously next time around.