Bearing in mind that I just started playing Witcher 3 this past weekend and have absolutely no experience with the first two episodes of that property, I'm enjoying the game. It feels more akin to Dragon Age: Inquisition than to Skyrim, Fallout 3, or New Vegas. The playing field is more limited, providing a confined sand-box versus having the whole world to explore as we do in Fallout or Skyrim, (At least so far as I've found at this early point.) though I expect each of the major areas will be built with a similar experience in mind. We will see as I progress.
One complaint so far: I inadvertently finished the first Act in Witcher and boarded the train before I'd wrapped everything up in White Orchard, finding myself railroaded into Act 2 in Vizimir with no apparent means of returning to where I wanted to be. And evidently Vessimir and I burned our bridges, so are unwelcome even if I COULD return. This is...well, very bad storytelling when you're running a tabletop RPG, and something I loathe in computer/console games. It's the biggest complaint my wife and I have against Fable 4, after all. (Having a story on rails, that is.)
The combat system is decent, with various options available (though a bit of a learning curve with the control schema for someone who has spent many many hours in gamesas worlds over the last few years.). Crafting is okay, though the cost to even dismantle items is annoying. Storytelling is okay, thus far, though there have been a few conversation choices that left me going LOLWUT in my head. The quests are okay, without too many fetch-quests as yet. I do like the witcher-sense lootable and forage container highlighting system, as it makes it easier to spot those items for...ahem, requisition.
Overall, I would like to say I'm enjoying Witcher 3 as a distraction until Fallout 4 arrives.
I am looking forward to the fully (or very nearly) sandbox environment of FO4, with the option to follow the main quest (or not) as I see fit. I LIKE being able to go "Oh, Alduin is coming? Okay, I'll look into it, but first let me clear this barrow here. And take this potion to that dude over in Windhelm. Oh, and I have to forge some armor so I can grind another level. Look, I'll get back to you when I can, okay?" I LIKE Bethesda's penchant for packing their maps with stuff to play with, look at, explore, and loot. I LIKE stumbling across the WTF things that are there because SCIENCE!
Does that mean I don't anticipate warts and dry-rot behind the peeling paint when the game comes out? Of course not. Do I think FO4 is superior to Witcher 3? For me, yes! For others? Maybe?