Ranked in these QuestionsQuestion Ranking
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 Written from scratch
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.
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.