I absolutely have and used it for a while before landing on opensuse microos primarily. I absolutely see the benefit and enjoyed the git-centric nature, keeping flakes in repos with a flavor for each machine. What I didn’t enjoy, however, was the seemingly poor documentation. Quite frankly too, the drama surrounding the community doesn’t inspire confidence either. I decided I ought to try out guix but haven’t gotten to it yet. I do actually still have one nixos VM that hosts some services for me and is built entirely on the concept of the impermanence flake. That was pretty cool.