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 18th.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Extremely fast
Pro Can detect incompatibilities
XBPS can detect incompatible shared libraries or dependencies and gives you options before installing.
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).
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 Allows partial updates
Pro Written from scratch
Pro Cross-distribution
You can install flatpak packages on any distro you want.
Pro fast
searching, installing and updating are faster than others in my experience
Pro Doesn't bog system down like snaps.
Plus it's not proprietary.
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.
Cons
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.
Con Unable to create packages under a non-xbps distribution
Makes maintaining packages a hassle.
Con Bloated
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.
Con Difficult to export packages
It is difficult and convoluted to export installed packages and move to another system.
Con Doesn't work well with CLI programs
Invoking CLI programs can be a pain. From the weird reverse DNS package names to difficulty in easily managing container environment.