Honestly, they've all grown on me, but I do have some questions regarding the narrative and game mechanic that make me raise an eyebrow or two. I think the biggest problem though is that while it seems that the game is hinting that each tadpoled character has been hand-selected to be a host, there's very little in the writing that allows a player to latch onto and then speculate about the *how* of it, for each companion. So instead of relying on characters' individual charisma or likability, having that aspect a bit more up-front would allow the player to be at least intellectually engaged with each companion's puzzle, trying to make sense of how they might fit into the bigger picture.
So in no particular order:
1. Gale. Others have already mentioned this, but the magic item consumption mechanic is a bit tedious to put it mildly. Afaik, he can consume potential story items,
like that beholder in the jar one can get from the smugglers or the Necromancy of Thay tome, even though that one seems bugged and you can give him the book infinitely
and that to me feels like a massive issue. It might be that this will have repercussions for future possibilities of those related quests, but there's no sign that this is the case. Minimally, if he's going to need to consume magical items, it would help if there was some kind of... idk narrative impact, warning, something. Or then we have to have a much better sense of (or relationship to) the magical artifact being consumed. But primarily, the way it's handled right now, is too much of a deterrent: I like the character, but why would one want to keep him in the party to begin with, he's a massive liability and his weave vampirism is a pain. If Larian wants to go with the vampirism/predation theme (we already have a regular blood vampire, why not have a weave vampire too, right?) then something more subtle, and less ham-fisted would be lovely. So to counterbalance that, if that mechanic could be tied, even through hints, to why he was tadpoled with the Extra Special Modified Snowflake Tadpole would be helpful.
2. Astarion. I don't mind him, if I squint, but narratively, I think it would be hugely helpful to have more narrative justification for why a, say, good or neutral or even lawful evil protag would risk keeping a vampire spawn around aside from him being pretty and uwu poor tortured baby. I think one way to do it is to start hinting early on (maybe it's already being hinted at, but I think it could be louder) that vampires might have a stake (har har) in the overall cosmological conflict, and that he might be useful as an insider, at some point. In other words, making it clear that he fits into the broader narrative in SOME way. One thing I dislike about Astarion, and he shares this with Gale, is that as written, it seems that they entirely rely on the player liking them personally, vs a player who is less interested in their extra specialness, but would be interested in asking how they fit in the bigger puzzle.
3.I've no problem with Lae'zel, she makes sense.
4. Shadowheart is clearly some kind of key figure, and in her case I can see the writing on the wall with that "broader conflict" question. She fits with the bigger story, so I don't really have a problem there.
5. Wyll. So I haven't gotten super far into Wyll's story but it seems to me that he also has a more clear tie-in with the overall story arc. However, again, maybe this is intentional, but his story seems full of massive inconsistencies, starting with the fact that he's in the grove when you show up, but claims he was on the ship -- it might be revealed that he's lying and a totally unreliable narrator, in which case, that's fine -- but it does make me feel a bit suspicious of him. Again, this might be part of a puzzle, but stuff with Wyll feels like it doesn't "add up" -- but maybe I just need to get more of his dialogue, idk.