When comparing Portage vs AppImage, the Slant community recommends Portage for most people. In the question“What are the best Linux package managers?” Portage is ranked 3rd while AppImage is ranked 10th. The most important reason people chose Portage is:
WIth portage you can decide and customize which dependencies to install through some thing called USE flags. These are keywords that when defined, will tell Portage that you want support for the chosen keyword.
Ranked in these QuestionsQuestion Ranking
Pros
Pro Decide which dependencies to install
WIth portage you can decide and customize which dependencies to install through some thing called USE flags. These are keywords that when defined, will tell Portage that you want support for the chosen keyword.
Pro Can install multiple versions of the same package simultaneously
Slotting is a feature which allows users to install multiple versions of a software simultaneously. This is especially useful for libraries which have changed interfaces between versions.
Pro Allows both binary and source installation
With portage you can either compile packages from source or you can download and install their binary versions.

Pro Simple overlay management
Adding supplemental repositories, aka overlays, is easy with eselect-repository or layman.
Pro You can view a list of programs that can be installed
With portage you can view a list of all the programs that you can install by going to /usr/portage
and running ls
.
Pro Sandboxes build process
Portage uses a sandbox as a safety measure during build processes. This is done to ensure that no packages accidentally write outside a 'safe' location.
Pro Respects customized config files
By default, portage doesn't delete or move any customized config files, thus enabling competent users to modify any config file however they want.
Pro Implements a standard with alternate implementations
If you need faster resolution, you can run pkgcore for search and portage for installing, and they work well together.
Pro Full control over installed packages
You can fully control all packages if you use it properly.
Pro No integration into the system
Leaves your system untouched.
Pro Easy to use
Just execute the package to run the software.
Pro Easy deployment of software
It just works across different distros.
Cons
Con Building from source take a lot of processing time
Most of Portage's pros are related to its "porting" process, building packages from source. This is very resource-intensive, with the few biggest packages sometimes taking even multiple hours to update or install.
Con Very slow
Dependency resolution is very slow and single-threaded, so usually you will see one of your cores running like crazy for over a minute.
Con Feature creep
It is very complicated and offers plenty of options.
Con High memory usage
Usually takes between 400-800MB of RSS (no problem to get over 1GB), so it's nothing for an old hardware.
Con You can not create packages under a non-portage distribution
Makes maintaining software for gentoo based systems a burden.
Con No wayland support
Apps look pretty bad on 4k monitors.
Con No automatic updates
You have to re-download the application to update it.
Con Big file size
