Guix looks really tempting to me because i find guile scheme so much more pleasant than nix. But i heard there are not that many packages in Guix. I wonder if some sort of transpiler from nix derivations to guix package definitions would be possible.
I've been running GNU Guix for five years now, after lots of distro hopping, including to and from NixOS. I left Nix because I found the documentation (particularly regarding the language) to be a struggle to work with (though I imagine it's improved since then).
GNU Guix + nonguix + flatpak is perfectly suitable for everyday use.