I like it just as much as I liked Fallout 3. Admittedly, I spent more time modding Fallout 3 than I did actually playing it. The main reason was because it kept crashing, official and unofficial patches couldn't fix it (and my system wasn't over-clocked at the time, haven't touched OC'ing in 7+ years by now). So I essentially forced myself to keep it installed to complete my mod, and once done I uninstalled it, and one day (months later) went on YouTube to watch the ending (original one). The constant crashing literally kept me away from it. I never bought New Vegas, due to the fear of crashing, so I went on YouTube again and watched a few "Let's Play"s until its ending.
So far, after 88 hours in my Fallout 4 game, I've had one crash, and only few minor game hiccups (floating corpses, weird physics of bodies especially in water, enemies spawning inside rocks or underground, A.I. getting stuck on impassable terrain with repeating animations, the usual Bethesda-flavored glitches) in rather low numbers. But, overall, Fallout 4 (at least for me) has been the most stable game that Bethesda ever managed to conceive, and for me that's saying a lot. There is no precedent for me. The only other decently-stable game from them I played was the original XBOX version of Morrowind, which occasionally froze from time to time, but was overall playable nonetheless.
So, generally speaking I can't really compare Fallout 4 well enough to either F3 or NV due to lack of a full game (from start to finish) experience with those two preceding titles. But at least from what I did play of Fallout 3 (which I still really liked, despite the crashing and freezing) I can say that - at the very least - Fallout 4 is just as fun, and this time I get to actually play it because it's a stable game.
The one "major" complaint (the only real one) I have about Fallout 4, however, is that everything there is to find (via exploration) at least on the surface is waaaaaaay too packed / condensed together. The feel of a "wasteland" is barely present when you literally find a new location every 20 meters regardless of the direction you walk to. The map, technically, is supposedly bigger than Fallout 3 (maybe it is, I just haven't looked at the details on that one), but regardless of that fact (it if is) it's still way too small especially considering that it runs on so-called "next gen" (current gen) consoles (that's the common denominator they built the game around for, we know that, but both the PS4 and XBOX One would have been capable to handle way more content especially with a game that still runs on [updated] GameBryo; c'mon Bethesda).
So if anything, I would have liked a much bigger map, in order to have more actual wasteland to have that loneliness feel kick in for more than just 30 seconds of walk time (which is usually interrupted by "Oh, look, I discovered something again, filled up by 15 paroling Raiders; damn son, overpopulation in the Wasteland? who would have thought!). But anyway, overall, I really, really like Fallout 4, and the big mods aren't even out yet (if you guys think what's available right now over at FO4 Nexus is good, wait until the official editor gets out, give it a year or so after that, then we'll start talking).