My installation is vanilla but with the DLC added. I haven't played through any of the quest based DLCs yet but am using objects from the Workshop DLC with no problems.
Admiring your weapon. One of the first things to impress me was just holding a pistol on my hand, moving it about to see it move in front of me like i was really holding it, admiring it from all angles. Not unique in the world of VR, but completely new to Fallout and such an enhancement. So real!
Scoped weapons. This feature wasn't initially enabled but arrived with a game update and works supurbly well. I find myself supporting my weapon hand with my other hand to steady the aim. Another tick for realism.
Grabbing stuff seems to be quicker and easier than before. Large number of objects can be picked up quicker. This surprised me a little and reaching for stuff is better, you can reach for objects that you coudn't reach before, reach through windows to get stuff.
Edit: the only slight issue is that for the VR version, grabbed objects move quickly towards the hand you're using to grab them, rather than just disappear from the world, which is good cos it's kind of realistic, but any objects they're in or touching can fly out of the way in the process. To avoid this I tend to position my hand above an open box that the object's in before grabbing so that the box isn't disturbed by the object's movement for example.
Analogue movement. This sholdn't be underestimated. FPSs all too often have consol type speed and direction change implemetations, meaning movement speeds are limited to walk/run/spring and directions are limited to one of 8 directions. VR almost always implements gradual speed changes dependent on the extent of the analogue stick movement and gradual direction change dependent on the direction of the analogue stick or the direction you're pointing the controller. So much more realistic and immersive.
Leaning around stuff, ducking behind objects, looking into stuff. Whether you're ducking a bullet, searching for loot or just admiring a singer in a bar! it's all so much more involving when you just move your head and body, rather than press buttons. I didn't bother leaning before but now I'm doing it all the time cos it's natural.
The scale of the world. Nothing to say here except you just don't understand world scale until you've played in VR.
Movement. This initially takes a little getting used to. Sprinting is initiated by a press-in of the left thumb stick (not my favourite control operation). A brief press and release is all that's needed, you carry on sprinting as long as you keep the thumbstick forward.
Movement direction is controlled by moving your left thumbstick in the direction you want to move or by pointing the controller in that direction... or a combination of the both. This becomes second nature pretty quickly.
Slightly annoyingly, sprinting is interrupted when you move your head more than 45 deg to the left or right, so you eventually learn to not move your head much when sprinting... and look around a lot when your AP runs out and your sprint is forced to reduce to a run.
Sprinting however isn't interrupted when moving in a different direction no matter how big that change of direction is, nor by quick turning, jumping or landing from a height.
Graphics: Resolution (per degree of visibility) is less, as with all VR games, and can lead to more surprise encounters with small critters which you may have noticed at a further distance when playing on a large decent monitor. Creatures like bloodbugs and bloatflies. This doesn't necessarily detract from the game but can add a little more chalange.
Unlike most made-for-VR games, Fallout 4 was created for displays that have many more pixels per degree and it's noticeable... and it's a game which makes me wish for the next gen headset, more than any other game.
Texture glitches. This happen occasionally and include distant scenery smearing (happens briefly and self corrects) and wet surface light reflections that change as you move your head (easily ignored and not really an issue).
Glitches and resolution aside, the world is just gorgeous. It's big and it's varied and it's full of life. So despite quibbles with resolution and a few glitches, graphics are good.
Using the weapons selection wheel can be a bit of a fumble when you're panicked (which is quite often). It's not as easy as pressing a weapon hotkey or moving a mouse thumbwheel. Also, if you happen to be pointing your controller at a character or object that has options available to it (such as a door or when your companion moves in front of you) the options for that person/object take priority over the ability to make the weapon selection wheel appear. This has caused my to die a lot! until I got used to automatically point up or away from the object before invoking the selection wheel. This is an inevitable result of having to cram so many options into so few controller buttons. You can see this as a problem or you can see it as adding to the challenge… I choose to think the latter!
The Not So Good
Melee. This used to be my default method for killing radroaches but it seems to be a lot harder to hit the target in VR. Now i just don't
Edit: Game crashes - Just like the pancake version, the game will crash (with roughly the same frequency). You may go though a week or 2 without a single crash, then it could happen twice in a single session. This is just the same as the pancake version, but in VR, when it eventually happens, it's much more jarring. It's like having your real world suddenly crash around you and it's unpleasant! but I'd say it happen on average, maybe 1 crash every 25 hours of play so I can live with it.
Swimming - Very glitched.
Entering water sometimes causes movement to lock. A press of either trigger re-enables movement.
Exiting water sometimes causes your weapon to lock in a weird visual way. Changing your weapon restores it to normal.
The swimming/wading through water sound is glitched and sometimes continues after you exit the water, cured by changing your weapon.
Swimming, for me at least seems to be silent.
Swimming under water is HARD WORK! requires lots of arm movement to mimic real swimming but you move by small amounts. It was a nice idea to implement swimming actions but poorly implemented resulting in a big reluctance to go diving.
At 268 hours so far, this is the VR game I've played more than any other, and at about 50% through the main quest, as well as the DLC to get through, there's plenty more still to do. So buy this game, don't rush through the quests, just enjoy the world and lose yourself in it... and be prepared to abandon all the important stuff you meant to get done on your New Year's resolution list!