I switched to NixOS two months ago. Was it worth it?
Yeah! Very much so. But there have been pain points.
For starters, I have a hunch. I think much of that bugginess on Fedora was maybe because they enable zswap by default. With zswap, under memory pressure, the kernel's oom-killer can't do its job effectively, requiring the use of a userspace one like oomd, which I have installed on Nix. Also, I did run into crashes on Nix, but after I enabled swap, those mostly went away when not gaming. (Why swap isn't enabled by default is a mystery to me.)
I don't find myself using flakes that much, because I don't know much about them, and I don't know how they fit in very well with the rest of this whole Nix thing, I guess. So my system still isn't a flake and I prefer to use shell.nix for development environments. But I did end up separating my config between configuration.nix and packages.nix for organization's sake, which I suppose is nice.
Speaking of packaging, I switched to nixpkgs unstable! So that's neat. I like having up-to-date packages, and every other unstable user I've talked to would agree that the name is a misnomer. Another thing I've switched to is Lix. I don't know what benefits it brings, but it seems to have fewer CVEs than cppnix, so that's cool. Apparently, it's more stable, but that's anecdotal--I don't have any data to back that up. Also it's gay--who doesn't love lesbianism?
As for the biggest, most agonizing pain point--can I just say how frustrating it is to get anything to build on this OS? You have to find all the dependencies of a project and put them in a file, which wouldn't be an issue if these things were better documented. But they aren't, so I have to spend an hour or two trying to compile, getting a linker error, and trying to track down the package that provides whatever library it wants. But at least it feels satisfying when it finally works, I guess? I dunno. If you know a better way, feel free to DM me on Discord at @.junidev.
So yeah, 2 months of Nix. It's going pretty well. I plan to get a new computer (and estrogen!) at some point later this year, so we'll see how Nix holds up with that.