Calling it solid is too kind.
I would say consistently low quality but serviceable. Rarely does a character say something that I'll reload to read again.
Characters on average are better grounded in the universe of the game, and I wouldn't say they feel haphazardly thrown about like in most shit tier rpgs, but they still feel like rpg trope inserts.I don't sense any ambition from their characterization or that of the factions.And the native shit with their Ekera Ekera is just cringe after a time. Only the queen seems intelligent and balances the native customs with the modernity of the setting, without coming off like some noble savage.
And that is when you're not being pestered by the weird, post-modern inanity of your companions.
Eder, aside from his odd mental regression from the first game (lacking the countenance of a war veteran) and the fact that every character seems to be telepathically aware of his farmer background, starts talking about fucking Xoti so loud that dogs started barking within 5 seconds of you meeting her.
Xoti is just an idiot who when she's not whining is giving poorly described explanations of her dreams. She is clearly in her late 20s or older but talks and thinks like a teenager.
Aloth is okay and will occasionally reference the events of the first game which I like. But the minute I start talking to him about past events, he starts discussing daddy issues. Which again, how old is he to have not squared this by now?
Teheku or the Druid manchild is some BDSM enthusiast degenerate (he has referenced this 3-4 times and shown me collar marks) who's constantly agog at mundane things and comments when adults with real goals are talking.
Maia is just an annoying teen snarky bitch whose characterization completely subverts the professional she's introduced as, with some 2000s era gag humor parrot.
Pallegina is also fucking annoying, but I forgive her because in my game I basically ruined her life by having her disobey the ducs. Still she rarely says anything that doesn't make me want to throw her overboard. Not only that but she also has some sob story from her childhood that she has unexplicably now decided to resolve after almost a lifetime of quasi-military service.
Serefan is tolerable, if only because he is a one dimensional pirate played straight. Not only that but he's basically Morte, in that he'll actually say something useful from time to time during a questline.
None of the above bodes well for the future of Obsidian, as most of the above represents the tipping point into the realm of AAA rpgs, where characters are just walking loot bags, quest dispensers, lol so quirky comic relief characters (think Moira from Fallout 3) or one dimensional plot devices.
You say the writing is at best solid and I say it is at best a vestige of F:NV and at worst a sign of things to come if Obsidian doesn't get its shit in gear and reassess their priorities.
Obsidian is not Bethesda. They can't just laugh off their buggy unfinished game while discarding one of their recognized strengths.