Nix support on Darwin is really good in my experience. Though it does happen that some packages are not supported.

Next to that I run a NixOS VM on https://getutm.app/ using Virtualization Framework. Performance is great.

You're one setting away `virtualisation.rosetta.enable = true;` to also use that VM for x86_64 packages and builds.

I have a WIP PR for Rosetta AOT caching on NixOS as well: https://github.com/NixOS/nixpkgs/pull/330829