I played it a little when it first came out, and there was not one thing I would say it did genuinely better than NV.
I'm not going to waste my time talking about writing, dialogue system, plot, lore, characters, skills/stats/builds, or anything like that because they're too abysmally shit to be worth it.
Graphics were bad. 3/NV may be bad too, but that doesn't mean 4 was good. Everything was muddy, ugly, and far more demanding on the hardware than was justified by the results. There were some things that looked good, mostly gear, which just introduced a contrast that made everything else look that much worse.
Combat felt a little better in some ways but worse in most. I liked that deathclaws actually felt like murderous deathmachines, except that they were trivially easy to cheese to the point it usually happened accidentally, and then they just because bullet sponges, which there were a lot of anyway. It was never possible with any amount of rebalancing mods to keep raiders more potent than ants beneath my feet while also saving me from dumping multiple mags into every super mutant.
Power armour felt great, but I never used it. I get that the fusion cores exist because they wanted a way to balance its power, but they were a huge annoyance I couldn't be bothered to deal with. And then there's the problem of its ease of access (which is part of the reason they needed fusion cores to balance it anyway…) and the strict level scaling for finding the suits.
Basebuilding existed purely to be a selling point. It was completely barren, soulless, and inconsequential. It was tied to a main quest faction as an added fuck you, and showered you with literally the most boring timewaster quests conceivable. The "settlers" were faceless automatons and filling their needs was simply ticking a box with no attention to making the settlement functional. Raids were magic bullshit that spawned inside your defenses and made walls useless. There was a huge amount of junk that you couldn't clear away and mods that tried to let you do so were hackjob workarounds that came with significant problems of their own.
Weapon and armour modding were good (and were a welcome reversal of the simplification trend we've seen in every Beth game after Morrowind), but it came at the sacrifice of actual diversity.
In both cases the resource gathering was an atrocious grind. You need to run around picking up every bit of junk you see in order to make shit, while the companions all moan about you picking up junk. Also, the fact that you could grow all the ingredients for adhesive, which you needed a lot of, and still have it all count as food production too meant that every settlement had the exact same farm; just one more way to drive out every last bit of soul and uniqueness from the mechanic.
Survival mode came out long after I had uninstalled the game, but I only need to look at the list of features to know I'd never touch it. Quick/autosaves and the console were mandatory based on my experience.
Features were cut from NV to 4, such as ammo types, that had no reason to be cut other than laziness and simplification.
I see nothing that would compel me to pick 4 over NV in any way.