So I have felt very torn during this thread. Because I get Ghost's point, but like others, I can picture MY character, but not necessarily someone else's from text. So I get Reimesu's point, and Faraday's, and Ganymede's... and I like pretty much everyone in this thread, (other than those I don't really know), so I haven't really put forth much of an opinion.
I've been accused of being a 'creeper', you've all seen the 'evidence' and arguments. Even if the person who accused me later said on that 'other forum' that she found the proof that everything was agreed to, and discussed (And never said anything here) - I was accused. If I was going to play on a MU again, I could never use that PB again - and I chose her because something about her clicked with how I saw the character. I really liked the PB. So I see how Ghost thinks some people pick PBs for creepy reasons (even I just picked her because she fit my mental picture).
But I still love PBs for others, it helps me shift the picture of who they chose, with things they pose or put in the desc that may not match up with the image, and create a slightly different picture in my mind. (I hope that makes sense)
Now, I have never used Midjourney, I have no idea how good it is. But I will re-state that I would love an AI I could feed an idea or image, with parameters to tweak, to make a more 'perfect' PB.