There have been a lot of questions I've seen popping up on discord servers, mmo-champion, and the official forums, and, rather than explaining everything again and again, this will be referenced instead.
Q: How is Mistweaver compared to other healers in Legion?
A: Healer balance has been at its best in a long time. Mistweavers are able to sit comfortably in any healing role that your comp may need, but we excel at group-wide healing. We can also deal damage without losing any throughput with two talents: Spirit of the Crane and Rising Thunder. These two talents are the Fistweaving build of the expansion.
Q: What is Fistweaving like in Legion?
A: Fistweaving no longer takes our damage and automatically turns it into a heal that goes to random people. Instead, we use our damage from Teachings of the Monastery from empty GCDs to regen mana in order to continue healing. Fistweavers also have a lot more uses of Thunder Focus Tea, adding more healing through a lot more Renewing Mists on your group at any given time.
Q: What stats should I be using?
A: It ultimately depends on if you're Mistweaving or Fistweaving.
Mistweaving: Intellect >> Critical Strike > Versatility > Mastery > Haste
Versatility and Crit scale roughly equally on all of our spells, except on Life Cocoon, wehre Versatility has a clear lead. However, the Damage Reduction component of Vers causes it to pull ahead of Crit very slightly. Haste affects more of our spells than Mastery, but both of these stats can be gained until you feel comfortable with their aspects; Haste for faster casts and more Soothing Mist healing, and Mastery for frontloading our common healing casts with more healing through Gust of Mists.
Fistweaving: Haste > Versatility > Critical Strike > Mastery
Haste lowers the cooldown of Rising Sun Kick, which effectively lowers the CD of TFT, as you're running Rising Thunder for Fistweaving. Crit and Vers scale better than Mastery for three of the four spells Mastery affect, and the damage boost from Crit and Vers make them pull even further ahead.
Q: Which level 100 talent is the best?
A: They are all competitive with one another. However, Rising Thunder is consistent between Dungeons and Raids, whereas Focused Thunder and Mana Tea are more situational between each other.
Q: How should I spend my Artifact Power for Sheilun?
A: My Sheilun post covers all notable Artifact traits and the two optimal paths.
Q: How do I use Essence Font effectively?
A: Essence Font has a lot of value within its HoT. Double Mastery heals are great for bursting someone back up quickly. There are certain breakpoints of Haste where you can fit in more casts while the HoT is up, but they're not important enough to build your stats off of. Every 16.67% Haste you gain, you can fit another GCD of either Effuse or Vivify.
Q: How are we going to Fistweave if we no longer have melee immunity?
A: I don't know how this rumor started, but it is untrue; we are not targeted by any encounter ability that won't target any melee character.