Wrote impressions in real-time in the other thread but having slept on it, here's everything from the first 6 hours:
Quests are stupendously boring and universally focus around combat. Ones I've had so far:
-Follow a BoS guy as he shoots a lot of ghouls, then shoots a lot of synths. Only the flimsiest of context is offered (we had to find a radar or something, which was never mentioned again after we got it by killing 500 synths).
-Raiders are attacking a settlement! Objective: "Kill all the raiders". And that's exactly what you do.
-Big museum with random villagers in it is under siege by RAIDER SCUM. Sneaked in, sneaked past the raiders and up to the room. Door's locked. Guy inside says "WE CAN'T OPEN THE DOOR UNTIL THE RAIDERS ARE DEALT WITH!" Kill 7 people, door mystically opens itself. Go inside, they tell me to get inside Power Armour and kill the rest of the raiders. I did a Shinji Ikari and refused to get in, they get pissy. Later went back and got in, you literally just shoot a lot of raiders and then a deathclaw who comes out of nowhere. Can't lose.
-Follow dogmeat. That's the whole quest. Dogmeat likes to run through packs of raiders, robots and feral ghouls.
Combat is improved from Fallout 3 but still sucks. Nowhere near good enough to carry the game. AI is notably improved.
Companions are a shower of cunts. BoS guy is shit, Dogmeat is shit (and keeps teleporting to me despite being ordered to stay and shot by me several times), Piper is a fucking idiot. All of them have about as much personality as the Fallout 3 or Fallout 1 companions, which is to say none.
Map is boring. If Fallout 3 and Skyrim were theme parks, Fallout 4 is the shitty local carnival of a remote Scottish village. All the rides suck, nothing looks good and you just want to get out of there as quickly as possible. Honestly about as much fun to explore as Oblivion, which is to say not at all fun.
Dungeons suck, theyre mainly copypasted skyscrapers where sneaking is unviable so all you can do is shoot everyone in your way. Skyrim looks glorious in comparison, where you could actually navigate dungeons according to your build - stealth, archery, all the schools of magic, melee, a mix of all of these etc. Fallout 4 has one build, guns, and that's what you're doing whether you like it or not. Unless you want to try melee, but why even fucking bother.
Charisma is occasionally checked in dialogue. This is always worthless.
Graphics are bad but serviceably bad, a la Skyrim. Nothing to really get worked up about, positively or negatively.
Writing is terrible, but not laughably terrible like Fallout 3. Instead, it's boring. The main quest is to search for your lost baby. Fine, as a plot device, not much different from a Water Chip or a GECK. But the entire main quest so far is just dealing with synths and The Institute. You're never given the remotest reason to give a shit about any of this, other than that they allegedly have your shitface baby. Dialogue is, again, just boring. A grand total of 1 NPC so far really had any kind of notable personality, everyone else (including the player) just says stock lines.
Overall, it's less of a Fallout game than Fallout 3* and less of a Bethesda game than Skyrim**. There's nothing really going for it, if you haven't bought it yet I'd encourage you to either pirate it or just not waste your time.
*Before you kill me, what I mean by this is that Fallout 3 had skill checks, skills, branching quests, a vague attempt at sticking to the lore. The writing was atrocious, the skill checks were all retarded, lore was completely shat on but it was still recognizably attempting to be a Fallout game, just doing a really bad job of it. Fo4 feels like a random sci-fi shooter, no skills, skill checks or alternate resolutions to quests, and it barely sticks to the lore at all. When you're walking around a random shanty town full of synths talking about how human they are and doing an interview for some lady's newspaper it's easy to forget this is supposed to be Fallout at all.
**I wasn't a huge fan of Skyrim but I hold it up as the culmination of the "Bethesda formula". They gave up on any window dressing at all and focused entirely on a combat-based open world dungeon crawler, which is their speciality, and it ultimately paid off. Fallout 4 feels like it's missing everything that Skyrim had.