I'm a opensuse tumbleweed user on my desktop and laptop. I also have an ubuntu home server.
I really like tumbleweed, but I have been thinking of switching to an immutable distro like guix or nix. I've tried guix several times and found it pretty good, but never stick with it due to its lack of KDE plasma support. Maybe I should give nix a try.
I was considering a switch to it and put it on my play-puter to see what it was like. Despite the alpha status, it was perfectly usable and I didn't have a single crash, perhaps I got lucky. I ended up staying with Tumbleweed in the end.