While unfortunately I have yet to receive a beta invite, and despite being overall optimistic for Legion, I am somewhat concerned about what I've read about the rate in which artifacts are upgraded. To my understanding, it takes a relatively lengthy amount of time to upgrade and fill out your artifact, and even more so when trying to do so with more than one. As one who enjoys playing multiple classes and specs, this seems like an issue that will ultimately funnel people into one spec / class.
I have seen feedback on this, but this is Blizzard in a beta we are talking about, so we will see. If the rate in which artifact power is acquired isn't adjusted to be more friendly to effectively being able to switch between different specs / roles, what do you all think about making artifact power be shared across all artifacts, thus having all 3 / 4 level up together. By doing this, healers (tanks?) wouldn't have to work twice as hard to either level up their character or make their weapon competitive, as well as easing the transition between DPS specs.