I run the complete system. It’s true that the standard iso comes with the linux-libre kernel and the standard channel (think repo) contains only free software. However there is the nonguix channel which comes with the full linux kernel, and all the proprietary drivers you could ask for.

Nonguix offer an iso with the full kernel too in case you have a proprietary wifi card and don’t have ethernet for the initial setup. The nonguix README I think is pretty clear, but Systemcrafters also made an excellent guide for doing this.

My wifi card unfortunately requires proprietary drivers and I have personally never had an issue with guix + nonguix for all my software needs, proprietary and otherwise.

Hope that helps profligate!