Haste > Mastery > Crit >= Vers
In raids, a good amount of haste will allow you to cast HoTs on more targets during your ramp while significantly improving your HoTs ticking, especially during Flourish.
Your mastery will have a significant impact, thanks to the multiple stacks you can provide to people through all your HoTs like; Rejuvenation, Germination, Spring Blossoms, Cultivation, Regrowth, Wild Growth, Tranquility & Lifebloom (even though this one will only be on one target).
Haste > Vers >= Crit > Mastery
This M+ build is aimed at improving your DPS & survivability (obviously two essential things).
If you really need more healing throughput to grasp the spec during smaller keys, for instance, you can add some mastery to be extra safe, though you should consider swapping stats after that and embrace the cat-weaving/owl-weaving. Unleash the beast within!
Intellect: Increases your spell power, which will boost your overall throughput.
Haste: Increases attack speed, spell casting speed and energy regeneration.
Mastery: (Mastery: Harmony) Your healing is increased by a percentage for each of your Restoration heal over time effects on the target.
Crit: Chance for extra effectiveness on attacks and heals.
Versatility: Increases damage and healing done by a percentage, while decreasing damage taken.
If you’re Horde, Troll will be the best-suited pick, thanks to Berserking, giving you 10% haste during some of your ramps.
If you’re Alliance, Night Elf will be the most common pick, not offering that much throughput, but mostly utility via Shadowmeld. In M+, especially if you’re pushing keys, this spell can be extremely good, allowing you to cancel some targeted mechanics, or to redirect them on someone else if you don’t have any defensive to handle them/want them to go on a class with an immunity.
Enchant Weapon: Sophic Devotion
Enchant Chest: Waking Stats
Enchant Rings: Devotion of Haste
Unique gem: Fierce Illimited Diamond
Standard gem: Keen Ysemerald
Healing Potion: Refreshing Healing Potion
Mana Potion: Potion of Chilled Clarity
Flask: Phial of Elemental Chaos (default choice)
Other choices are Phial of Static Empowerment (it will require you to stay idle most of the time) or Phial of Charged Isolation (it will require you to be far from other people) ; both of these conditions are difficult to meet, and you probably won’t gain the full value of these phials.
Rune: Howling Rune