I am doing significant Nix/NixOS stuff at work recently. I think Nix/NixOS may be the future of Linux or the basis for a new project that will be the future of Linux (competing with container-based distributions). It's really innovative and the benefits are significant.

One of my main concerns is that Nix/NixOS being so alien, a lot of work is required to bring it up to the maturity of more conventional environments.

https://github.com/cloud-gouv/securix is quite interesting.