I do!

For starters, you're not required to install Guix System in order to use the Guix package manager itself; the manual provides instructions for installing it on top of your existing system here if you want to use it but not fully commit (you can do this with Nix too).

Guix allows for adding new sources to pull packages from using channels. The nonguix channel provides the Linux kernel - blobs and all - as well as other stuff that won't be upstreamed, like Steam and NVIDIA drivers.

I recommend this helpful series by System Crafters, which includes a few guides on installing Guix and Guix System with the full Linux kernel.