When comparing NixOS vs Solus, the Slant community recommends Solus for most people. In the question“What are the best Linux distributions for desktops?” Solus is ranked 10th while NixOS is ranked 16th.
Ranked in these QuestionsQuestion Ranking
Pro State of the art package manager
Atomic non-destructive upgrades / rollback of a system upgrade / declarative reproducible system configuration / unprivileged installation of packages / transparent source or binary deployment.
Pro Reproducible System
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.
I have never had a package break on me after a NixOS upgrade as I have with other distros (especially Arch).
You can start with a minimal environment and add packages and software to suit your needs as you go along.
Pro Rolling release
Pro Modern desktop environment
The default desktop environment used by Solus is called Budgie and is quite nice and minimalistic.
Pro Easy installation
The installation procedure for this distribution is quite simple. It's GUI based and all you have to do is to follow the instructions given by the installation window itself.
Pro Exclusively for desktop systems
Pro Great package management
The software center makes it really easy to install the latest software through Snappy and Flatpak. Including third party software.
System boots quickly and stays responsive. Does what operating system should do, and does it really well.
The system itself is very stable. All packages in the repository seem to be carefully picked, well prepared and run stable.
Pro Seamless Packages
It may not have the most obscure packages, but the packages it does have is a good number of everything a Linux user needs. Gamers, developers, desktop users, etc. all have the necessary packages and then some. The packages themselves are integrated perfectly and are very well updated.
Pro Most stable Rolling Release Distro
Pro Built from scratch
Con Documentation is not good
Con A configuration change might end up bricking your system
Con Uses a text-based installer
Con Slow development
Con Software a bit slower to launch than for other distributions
Con Not much software
There is not much software available.
Con An upgrade breaks the system quite often
Con There is often a black screen after update
Con Forums are not very friendly
Con No USB Image writer
Con The default desktop environment is not very customizable
Maybe because it's a relatively new project still in its infancy and this may be fixed in the future, but Budgie is not very customizable. You can only change the theme and wallpaper.