I took this as an excuse to try NixOS myself and an opportunity to provide anecdata.
Previous Linux experience: Lots, including about 7 years of Gentoo use, some Arch and the usual distro hopping before that. Mostly on laptops (not counting VMs). Lately it's mostly been the BSDs so I'm a little lost.
It took me about 45 minutes from searching for their site to have a working XFCE install using their minimal install ISO with VirtualBox. Certainly a different experience, but with their install guide and searching "nixos xfce" you'll get it done.
Promptly rebooted and went for an encrypted ZFS root - less straightforward but after a few PEBKAC snags I got it up in an hour or two.
My immediate impression is that this is great but not being allowed to just
# which zsh >> /etc/shells
rubbed me the wrong way. Definitely something I'll consider using in the future, seems like a good fit for i.e. a VPS you might want to move easily.Naturally I haven't learned the config language fully, but it seems easy enough if the docs aren't terrible.