I use NixOS unstable on my desktop/work machine, but when I just started using NixOS, I even regularly hopped between the latest stable release and unstable.

Another fun related feature: NixOS really only requires /nix and /boot to boot. So, some of us just nuke everything except /nix, /boot, and /home on boot:

https://grahamc.com/blog/erase-your-darlings