There’s a couple of absent macOS-specific packages, compared to homebrew. So I have `trash` and `pngpaste` declaratively compiled-from-github in my nix config, but that's the only two I'm missing compared to brew. (That said, I never dealt much with brew-cask, so if you have a host of GUI packages from that, you may be missing more)

If you're on an M1 Mac it will use x86 binaries by default, running under Rosetta. The situation is improving - I use almost all of my packages in native aarm64-darwin - but it still requires using bleeding-edge code.

The learning curve has been pretty brutal, but I really like it for both managing my system-wide (well, user-wide) software, and for pinning to explicit package versions in a large ruby/javascript project.

I do that for my work machine which is a MacBook Pro.

You still need to install most GUI apps through the normal non-Nix procedure.

You also won't be able to use the Git module in home manager since that will use a version of Git that doesn't understand some MacOS specific customizations, mostly surrounding Keychain if i recall correctly.

Most packages just work on MacOS but it's not a first class citizen and there are always more packages broken for Darwin than Linux.

But I'll say it again, I tend to dabble in plenty of programming languages and often run software that's a bit off the beaten path and Home Manager and Nix on MacOS work 95% of the time for me.

Nix has over 80k packages now, so odds are what you need is there. But you should verify everything you need is available before switching. Make a list of everything you need and search the package repository for it:

https://search.nixos.org/packages