I'm basically updating the below post and followups for 100% crit heals. Credit goes to the original poster.http://us.battle.net/wow/en/forum/topic/1083320196?page=2#23
Healing crit multiplier = 200%
Ancestral Awakening procs on single target heals for an additional 30%
Crit is a 160% increase on single-target heals (1.3 AA * 2 crit mult = 2.6)
Crit is a 100% increase on multi-target heals (1.0 AA * 2 crit mult = 2)
For each 1% crit, we get a 1.6% throughput increase on single-target heals and a 1% increase on multi-target heals.Haste:
1% / 128.06 = (1 - Health) * 3% / 179.28
Mastery rating is better than Haste rating when target's Health <= 53%Crit, Single-Target:
1.6% / 179.28 = (1 - Health) * 3% / 179.28
Mastery rating is better than Crit rating when single-target's Health <= 47%Crit, Multi-Target:
1% / 179.28 = (1 - Health) * 3% / 179.28
Mastery rating is better than Crit rating when multi-target's Health <= 67%
So there's the new math; crit is obviously much improved, but gearing is largely unchanged. If you're tank healing and your target frequently gets below 50% or so, gear for crit over mastery. If you're AE healing, gear for mastery.
Interestingly, crit now outpaces haste for single-target throughput, but is obviously less reliable.
I updated the FAQ with this information as well, including a quick summary line.
Please let me know if my math is wrong anywhere.