Have you tried FreeBSD before? It ships with an awesome binary package manager and a virtual tree of sources for all the packages in the package manager at the same time. You can install the binary (sudo pkg install foo) or cd into the source dir, fetch the sources, patch on a whim, then “make” (even if the project upstream does not use make) and install.
I have used ports (if that is what you are referring to) albeit on a mac. It is very basic, without any of the interesting properties that make nix interesting. It essentially feels like a slightly improved "download && ./configure && make && make install" script.
Ports is great. I have only used FreeBSD lightly, but macports is the only package manager for OS X that has been reliable for me. Nix is not a strict improvement, but it improves things in a lot of directions compared to ports.
Hardcoding dependencies at build-time seems to me like a fundamental first step towards a stable system that has been absent from Linux since the late 90s.
