NixOS vs SparkyLinux

Atomic non-destructive upgrades / rollback of a system upgrade / declarative reproducible system configuration / unprivileged installation of packages / transparent source or binary deployment.

You can start with a minimal environment and add packages and software to suit your needs as you go along.

NixOS is configured using the Nix package manager, allowing your system to be replicated and kept in sync across multiple machines. Great for keeping a laptop and desktop in sync.

Packages don't break after a NixOS upgrade as they are prone to with other distros (especially Arch).

You have access to a large user repository, Ubuntu guides can mostly be applied since both are based on Debian.

You have the option for Sparky to be based on Stable or Non-Stable, bringing greater flexibility to user priorities.

Sparky is designed to be lightweight in it's core. It is based on Debian but optimised for old hardware, meaning you can run a full heavy desktop environment on a lightweight foundation, bringing greater performance compared to similar Debian or Ubuntu-based distros.

Any Linux desktop in it's vanilla form can be installed on top of Sparky, whether that be alongside a pre-existing environment, or on top of a basic command line system. Furthermore, the command line system is easy to operate due to Sparky's advanced installer utility, from which you can choose whichever desktop environment you desire, straight from the Debian repositories. Guidance is on their website.