When comparing XBPS (X Binary Package System) vs Flatpak, the Slant community recommends XBPS (X Binary Package System) for most people. In the question“What are the best Linux package managers?” XBPS (X Binary Package System) is ranked 4th while Flatpak is ranked 17th.
Ranked in these QuestionsQuestion Ranking
Pro Extremely fast
Pro Lots of features
XBPS can not only be used for installing/removing packages, but it can query for package info (such as version, dependencies, size etc), reconfigure packages, report and fix issues by modifying the package database, search for alternatives, manage local repositories and various other useful tools.
Pro Can Detect Incompatibilities
XBPS can detect incompatible shared libraries or dependencies and gives you options before installing.
Pro Written from scratch
Pro Can Install Binaries or Build From Source
When installing software you can choose to install binaries or build it from source (natively or cross-compiled).
You can install flatpak packages on any distro you want.
searching, installing and updating are faster than others in my experience
Pro Application sandboxing
All applications are limited to a set of predefined permissions, enhancing privacy and security.
Pro A well-written documentation
Pro Flexible runtime management
You can install a lot of runtimes for different apps, making applications a lot more compatible while still allowing some applications to share their runtimes.
Con Not just one command to run
It's not a very big drawback, just not as convenient as one command with multiple options to remove and search for apps.
Due to the way Flatpack handles packaging, this can lead to a large cache being created which quickly inflates to unreasonable sizes. Not only this, but using flatpack requires a large chunk of space to be reserved for it's own file hierarchy.