I like the sound of nix but the disk space issue is a deal breaker for me - my sdd is always full.

I run my main arch system in under 6GB. That's enough for qemu and wine and a few other bits which is all I need - the rest is in VMs

Would like to switch it to nix though..

I think, like everything with Nix, if you recite the correct incantation for configuration you can avoid this issue. But it’s not default behavior