Вы читали вот тут все соображения и расчеты про статы?
https://sacredshielding.wordpress.com/legion-guide-stat-priority/Главным образом вот этот пассаж про хасту:
"Haste has several interactions with our abilities. It reduces the global cooldown from 1.5 seconds to as low as 0.75 seconds with 100% haste; it reduces the cooldown of Holy Shock, Light of Dawn, Judgment, Crusader Strike, and Consecration; it reduces the cast time of all of our casted spells; and it increases the frequency at which the healing of Tyr’s Deliverance ticks.
All of these interactions do provide an increase to our HPS, but it also has the negative effect of increasing the rate at which we use abilities and mana. Crit, mastery, and versatility increase both our HPS and our healing-per-mana (HPM). Haste increases our HPS at a relatively similar rate, but it has no affect on our HPM. This is very important to healers in Legion as we won’t be seeing an increase to spirit over the course of the expansion. This doesn’t mean we should avoid haste, but that we should be mindful of this fact when acquiring gear.
Haste also has no affect on a few of our abilities: Light’s Hammer, Bestow Faith, Aura of Mercy, Holy Prism, and Judgment of Light. Haste does reduce the cooldown of Judgment, but haste would only benefit Judgment of Light if all of the charges were consumed before Judgment came back off cooldown, which sometimes doesn’t happen in raids and definitely doesn’t happen in dungeons."