I use Debian for servers. I recently began migrating from Arch on my desktops to NixOS. The shift from the fantastic Arch wiki documentation to the NixOS documentation was a huge stumbling block, but I got through it. It took a lot of time to get NixOS to a nice state on my main laptop, but once I did, installing it to my 2013 macbook air and configuring it to be exactly like my main laptop took all of 15 minutes. That was a huge deal for me. The next hurdle is going to be installing it on my desktop with nvidia GPU, but I don’t expect it will take too long.
I’ll probably start migrating servers to NixOS where I can, too.