Honestly I think those that think playing as "origin" characters are going to offer anything other than a slight diviation from the plot will feel let down.
If they use the same formula as DOS2 the origin characters will have few short side quests to resolve their "unique" personal paradigm. Astarian will kill vampire master, SH will deliver the McGuffin and regain memories to find "shocker" she was a brainwashed Salunite, Gale will get orb thing removed etc. etc....
The difference I see between the DOS origins and the BG:3 origins is that in DOS they seemed like an afterthought, no one's personal storyline really fit into the main storyline, they kind of just happened, they didn't even really interact with each other, such as you might expect between Sebeille and Ifan or the Red Prince. I don't think that's really the case with BG:3 because everyone's personal problem seems to be related to the main story in some way, Shar is clearly a big part of the story, She and the Gith are looking for the dodecahedron, Netherese magic seems to be at play with altering the tadpole bringing in Gale, Hell has another role, we find a lot of soul coins, fallen paladin's in service to Zariel and we've learned that the Justiciars fortress was destroyed by a Hellish host, bringing in Wyll and possibly Astarion, for some reason I think there's a connection between Raphael and Cazador, also the Hag we'll be meeting in BG. None of this means it will be any good of course, but unlike in DOS I see at least the groundwork for a more interesting story.
I think the original BG games and Dragon Age nail what it means to be a protagonist in a CRPG.
You have freedom to create any kind of character, but you have a unique connection to the story. Your companions are important, but there can be only one protagonist in a story. Larian is trying to reinvent the wheel and use four protagonists. It's more like a competition who gets the spotlight, and the custom PC will lose.
I don't think there's a problem having a story with multiple protagonists, a fellowship of heroes, and having a bunch of egos butt heads throughout the story could be very interesting.
Dragon Age is an good spectrum of MC customization, Origins because they devoted a whole section of the game to defining who your character is, a section of the game that would change radically based on your race class or gender, meant you could understand not only the world you're in but how your character fit into it, it made roleplaying the PC later much more satisfying. DA:II stripped that back quite a bit, but it still hand a very defined backstory upon which you influenced the nature of your Hawke Act to Act, then DA:I where it was almost nonexistent, the backstory reduced to a blurb underneath selecting your race, and only was significant once or twice during dialogue, and again during the map minigame (time sink). I think most people would agree that Origins does it best but I still think that a compelling defined backstory like in DA:II was head and shoulders over Inquisition where half-way through the game someone says something to remind me "Oh, right, I grew up as a noble"
The custom PC will lose out as long as they don't receive a backstory. Either make one, let us choose one, or we'll have to be happy with the generic_hero, who will be significant to the story only because they have a special tadpole and happen to be played by you.
