12/19/2010 5:18 PMHoof, that's not entirely true. If the haste gets your efficient heal's HPS output high enough that you can chain it instead of using your big heal, then you are saving mana because the efficient heal is, as the name describes, more mana efficient in terms of turning mana points into hit points.
Posted by Sevzi
However, that haste breakpoint is something like 50-100% haste for most casters.
That only holds true if you have to emergency heal, which doesn't happen that often, and when it does, really makes mastery shine anyway.
Assume crit instead of mastery:
If you can output 6k hps, whether you do it with 5 hastened HW or 3 unhastened ones of which one is a crit, you are still healing for 48k over 8 seconds (numbers pulled out of thin air for the sake of example). Your recovery over 8 seconds went EXACTLY the same.
In WOTLK, this (empowering slow heals) wasn't viable, because at no point in time you had 8 seconds to heal somebody, but that was ok, because we all were mana batteries.
In Cata, mana is a precious resource, but you ARE given time to heal AND you can now heal while moving for 12s every couple minutes, and we can still insta a big heal every 2m (plus now we can unleash it too). This is why just stacking haste isn't as desirable anymore.
If you consider mastery in the comparison instead of crit, your number will be the same, except your biggest healing in that 8s span happens when it's needed the most, at the lowest percentage.
In all cases, Haste is excellent recovery utility, and great for mobility, but the argument of "you can cast more smaller heals" doesn't hold any water, as that, in a context where you have time to heal, aways boils down solely and exclusively to HPS, whichever way it's achieved.
The argument to try and make haste look like good hpm is highly artificial, crit is and will always be the best hpm, with mastery 2nd. At least for shammies. Of course other classes have massively different priorities sometimes.