I loved the companions in DAO. Their personalities are etched into my brain at this point, and they truly feel like old friends. Of course, the game had such high replay value because of the origin story concept, that I experienced every little snippet of everyone's personality in my gazillion playthrus of that game. No other game really nailed choice and consequence like that game for me either, both in terms of how your companions reacted to you and how the entire game played out.
*sigh* I would love to fire it back up, but it would take a whole day to find all the essential mods at this point. But the spell combos! And getting to set the tactics for your party! That mechanic also contributed to how I viewed my companions as well. For example, if I was romancing Alistair, I would set him to shield bash anyone who came near me. I would always set Sten to rush headlong into battle. And Morrigan would demolish the field with spells. Leliana would pepper the battlefield with arrows while singing crazy songs in the rear. Gah! Tactics + great writing = best companions ever for me personally.
I also loved the ME series chars (not counting MEA, which were atrociously shallow). Anderson...Legion...Mordin -- *sniff*. WHY?????? *sniff*
I think this game has great potential to be as good as those games in terms of companions. The writing is fine and the voice acting is really excellent. Sure, there is cheese in the writing --- but I have never played a fantasy game ever where there was NOT a healthy does of cheese. Especially in the romance scenes. One must learn to master the cringe, let if flow through you, etc.
But seriously --- I am actually rather invested in seeing their stories play out. My only gripe is that they show absolutely no interest in *me*. In DAO, all the chars would ask about you, and you would get a chance to respond.
Sten "Are you a woman?" LOL. But even Alistair shows concern over how you feel after Ostagar. Wynne is all about listening to you and offering advice to keep you focused. Even Zevran is curious about you...and he was sent to kill you!
NONE of the companions in BG3 show any interest in my char whatsoever --- until they all decide to hit on me at the party. (yech). That would be the most important thing that needs to be fixed in this game to really elevate the companions, imho.
Also... I really hope they don't pull a DOE2 and force you to choose only a subset. I really dislike that. It makes it feel like the intro area is nothing more than a popularity contest. I find it icky. I also think this is why they all hint at "dark secrets" and all that so early --- to basically beg you to choose their story to pursue. It is a shame, and frankly takes a bit of the fun out of it.
But I will reserve my judgement until the completed project is out. So far, I am digging it. The issues I have with the game are more about some of the mechanics that make combat way too easy. In terms of the story, I am interested to see where it goes, and how my companions evolve as we go there together.