I have to second Spiritus. Yes, I'm a little disappointed with my mana not being where it use to be, but most of that is more shock value and having to get use to actually thinking about what spells to cast instead of casting whatever I felt like. Personally, I think Prayer of Healing is in a pretty good spot. The one thing I liked about Priests above other healers was that they had good, steady healing, but when it really hit the fan, I always had the option of lots of burst healing at the expense of burning through my mana. Before 3.1, I never felt like I could really do that, where I was pretty much spamming my optimal raid healing rotation, and it was either enough, or it wasn't, but I never had serious mana problems and I never had those emergency tools.
I finally feel powerful again, where I know I can throw out more HPS than anyone else in the raid by a considerable margin, but it's balanced by burning through my mana very quickly. And, thankfully, it reintroduces a variable that allows a skilled Holy Priest to separate him from a bad one. Unlike CoH where even someone who facerolled could do it pretty much endlessly for obnoxious HPS, we finally have our throughput back, but in a way that can't simply be facerolled.
So, sure, would I like it to be a little cheaper, why not. But when you think about it, by the time the vast majority of us are doing hardmodes that might make us want to be able to spam it even longer where than 5% might make a difference, we should have picked up a few pieces of gear that will balance out that 5%, and everything will be fine again.
So, yeah, let's not whine about PoH; the fact that you can't spam it endlessly is a GOOD thing.