I feel that Mistweaver is quite comfortable to play, but very sub-par compared to the other classes atm. It has two distinct healing styles, Vivify or Essence font focused, which strongly depend on healing setup, and encounter. I don't raid in a top end guild, but did clear EN Mythic and got the cutting edge, but we only managed to get Odyn down before NH was released. Now we only raid NH, we raid 2d/week and we've cleared 3/10 so far and got Spellblade to 12% last night.
We raid with a paladin, two shamans, a holy priest, and me as MWer, and that's pretty much been our healsetup since the expansion was launced. HPS-wise, I'm nearly always 1st, and I've managed to get some high ranks (99-100%) on warcraft logs, which comes down to alot of things, and isn't the point I want to make. I'm the healing officer in my guild aswell, and I always receive Blessing of Wisdom, and atleast 1 balance druid innervating me, usually two druids.
In NH heroic, MWers are absolute batshit crazy good, and we top alot of the fights. But in early NH mythic, I feel it is very difficult to keep up, if BoW and Innervates aren't available.
-I really enjoy playing Mistweaver, i feel it is very rewarding to play, super mobile, and lovely animations!
But I do agree, that alot of things need re-work, sheiluns gift for one, and I'm very much looking forward to the reduced CD on revival for 7.2.