So, I've been wondering about PvP itemization in Legion for quite a while now.

Like, how will the artifacts work in PvP in terms of Artifact Power, "relics" (the ones that upgrade the weapon itemlevel etc.), and how will both of these compare to PvE?

Also, I know they mentioned that you can get items from BGs, like now, with the strongboxes, and the rewards will be directly tied to your RBG/Arena rating, which is fine, but it would be nice to know in detail, how good the PvP items are compared to ie. raid items, and if said items will be scaled down or up, like they do currently, or will raiders just have an advantage?
I know they mentioned the 7% difference at gamescom, for a just dinged player, compared to a mythic player, but there has to be some technical information on how that works.

And all of this matters because, if items dont scale up/down, and PvP'ers get lower itemlevel gear than raiders/high keystone CM, this could be a significant difference in terms of raw output and survivability.