The game is overall better written than FO3 that's for certain (not that it's much of an achievement but still). I can't remember anything from that game beyond the silly bits that made me facepalm like Little Lamplight, the Tenpenny Towers quest and how stupid the existence of Megaton is.
FO4 has a few nice, Bioware-eque companions (Piper, Cait, Nick, Hancock, I also like Codsworth) and some of the NPCs are fairly well written and voice acted, such as Maxson and Father. The central conflict between the factions is very New Vegas-esque, which is nice, even if the factions themselves aren't that interesting apart from the ''back to the roots'' Brotherhood. The Minuteman are flat goodie two-shoes, the Institute are the Think Tank with a prettier face, and the Railroad are just lame, who cares about android rights in a post-apocalyptic wasteland anyway.
I also like how many companions have numerous environmental comments. They react to your explorations quite a lot, which is very nice, and some decisions will earn their disapproval.
Unfortunately a lot of that is hamstrung by a PC that is not allowed to emote often enough, especially considering the traumatic events they live, the awful dialog system, janky and bad looking pseudo-cutscenes, companions liking or disliking you for mundane actions (Cait literally fell in love with me because I lockpicked enough stuff and took drugs, that's even worse than DA:O's gifts), and ye olde Bethesda problem where you're encouraged to ignore the main story entirely in favor of going who knows where doing who knows what for the lulz, even if your primary objective is quite urgent and important.
It's a good effort in terms of writing, honestly. Definitely Beth's best written game in terms of characters at least. It's just that typical Bethesda idioms get in the way of the story's enjoyment. Dragon Age: Inquisition had this problem too, but nowhere near to the same degree if you ask me. At least even mundane quests in that game helped the Inquisition, setting up a farm for 2 generic NPCs in the middle of nowhere doesn't help me finding my son.
I agree that FO4 is a good step or three forward for Bethesda.
Far better in nearly every respect and mechanic than FO3, and arguably a peer competitor for FNV. FNV is 'sharper' in some ways- a bit more on-punch in the writing, a bit more developed in the companions, and a better reputation system overall- but FO4 is no slouch. Not only did it innovate and improve upon the crafting system, and innovate the settlement system, but there's a respectable balance overall between the factions.
While I miss the factional reputation system of FNV- I think it would have worked well in the context of the multi-faction cloak-and-dagger quests where outright conflict was hidden- the handling of the Institute overall was a good attempt. Not flawless by any means, but far, far better than the handling of Caesar's Legion in FNV. As a designated 'evil' joinable faction, Caesar's Legion had almost nothing to speak for it- it offered one sort of security (safety from raiders) that every other faction did, and many significant harms as well. The Institute has crimes as well- but few as serious, none as deliberatly cruel, and offers real and practical potential for public good depending on player action.
FO4 has a good balance of factions, which I heartily approve. There's merits for, and flaws against, each and every faction- both moral, ideological, and pragmatic.
The Institute is the epitomy of Ivory Tower intellectual elitism and disconnect from the world, for good and ill. It is misunderstood- but for both better and worse.
The Brotherhood of Steel offers real protection for the Wastelanders, at the cost of racist hostility against a minority (non-feral ghouls) and the worrying establishment of a conquering empire.
The Railroad is moral conviction, but ultimately indifferent to the fate of everyone and self-destructive of their own cause. They have no plan for the future, existing only for a specific cause of the now.
The Minute Men are are force for good... for the moment, and have a weak organizational purpose or resiliance.