Perhaps what I was most excited about with Blackwood/Companions was the prospect on running random dungeons with a friend and our two companions... But as more and more information about the companion system comes out we're hit with this stipulation, "Players will always take priority over a Companion."
This means that it will be impossible to queue with your companion for content as it'll just get replaced by a player by the dungeon finder.
I understand the fear the devs might have about trying to manage queue times if people are playing with companions, but I think it would really be good for the overall health of the game (and its playerbase.)
Almost every day we see some post on reddit from a player who's infuriated about getting a "fake tank" or people speed running dungeons that they want to take slow. Just, so, so, many drama-infused-posts from people basically BRAGGING about them and their friend kicking someone at the end of a dungeon because they speed ran it without waiting for them to "teach them a lesson"... Companions would solve all of this--especially because one of them is a tank. Those of us looking for quick transmute crystals could power through randoms with our companions, and people who want to take 7 year old content at a snails pace can do so... No more drama.
I guess another solution could be moving the daily transmutation crystals out of the random rewards and into some sort of random dungeon quest (so you could solo or two man it), but that's a different issue.
TLDR: Let me and my friend use companions for fast/drama-free daily rewards!