I agree and add Void Linux to the list in the same vein.

Generalley, ports-like package repos (all package build recipes in one repo) are really beneficial for large-scale operations or simply rollbacks. Being able to bootstrap the distro from a git repo and a well-defined set of bootstrap tools is really nice. try that with debian.

See Void Linux and Alpine for a simple, yet refreshing aproach to distro package maintenance, with low overhead.