I haven't really commented about the upcoming mana cost increases for Holy paladins in 4.2. I'm still waiting to see how things pan out. Though naturally the forums are up in arms over the changes.
But I'm coming to the conclusion that there is too much mana regen running around these days. In a lot of respects, it feels like my mana bar is swinging around wildly during fights these days.
We were doing Heroic Maloriak the other night. On the first attempt, the phases at the end of the fight went Blue->Red->Green->P2. I entered the Green phase with about 40% mana, which in retrospect was a bit too low.
On the second attempt, which was a kill, the phases went Red->Blue->Green->P2. This time I entered the Green phase with 90% mana. This is because the healing needed in Blue phase is pretty light, making it a total regen phase. Pop Divine Plea, cast Holy Lights instead of Divine Lights, etc.
Sadly, a lot of my mana went to waste because WoW crashed on me in P2. It was quite infuriating. Why didn't it crash the previous attempt when I was bone dry?
But this "swinginess" of mana seems too much to me. Bouncing around from 40% to 90% and back down is really weird. If a fight has a regen phase, you can gain a ton of mana back, probably too much.
Personally, I'd rather Blizzard nerf mana regen rather than increase costs. It seems like it would make healing mana more stable and predictable.