Not what the OP asked, but:

Initially, I really wanted to use Guix over Nix, but Nix is more mature with more packages, maintainers, and features.

Last I checked, for example, there was no equivalent of a channel or overlay in Guix. Their npm importer was also not released, whereas Nix has a very usable node2nix.

Having done virtually no functional programming, learning Guile Scheme was also a barrier to me, but the Nix expression language felt a lot more natural for whatever reason.

It's unfortunate - I'm very interested in the work in reproducible builds and substitutions Guix has done, maybe it'll take off at some point or those features will be integrated into NixOS.