I read a post by Gardiff on MMO-Champion that I think is intriguing. Basically, he suggested that even though he is maining as Resto throughout the xpac, he is starting in enhance and putting 11-13 levels of artifact power into his enhance spec before beginning his resto spec. His reasoning is that even though he will be a little behind in the resto artifact power at the start, the QoL will be vastly improved while doing quests and such at level 110 as enhance with a partially-filled artifact weapon.
His quote, “I never felt weak starting off heroics as resto with a 0 point artifact. Once at 110, you’ll be surprised how rapid the gains come from some quests in suramar (which are not knowledge-based and so they just provide a large flat amount)…However, the bigger reason for me is not the leveling process. At 110, healers don’t scale as well as DPS. They are still behind on the leveling process, but its not as far apart. I can still burst 400-500k (and sustain 250-300k) on my enhance on certain quests while my resto shaman can’t reach 100k. Between things like the suramar scenario and just basic world quests, things at 110 will be very slow as resto. You may be able to rely on tagging, but with a 6 second flame shock CD, we are not really the best healing class to be tagging multiple mobs to get credit.”