When comparing OpenSUSE vs Slax, the Slant community recommends OpenSUSE for most people. In the question“What are the best Linux distributions for desktops?” OpenSUSE is ranked 14th while Slax is ranked 54th. The most important reason people chose OpenSUSE is:
The packaging team is dependable resulting in system updates that come in a timely fashion and systems which rarely, if ever, break due to packaging. The versions of software that are selected and the configuration of them is typically extremely high quality.
Specs
Ranked in these QuestionsQuestion Ranking
Pros

Pro Extremely reliable
The packaging team is dependable resulting in system updates that come in a timely fashion and systems which rarely, if ever, break due to packaging. The versions of software that are selected and the configuration of them is typically extremely high quality.
Pro Easy installation and administration
openSUSE makes use of a GUI tool called YaST to install and setup an openSUSE system.
YaST is very easy to use and makes the process of installing and maintaining an openSUSE installation a breeze.
Pro Easily get packages from other sources
SUSE Build Service offers packages from the same sources as Fedora, Debian, Ubuntu, SUSE Linux Enterprise and other distributions. This is the most underused package tool in Linux today.
Pro Probably the best KDE desktop experience
Both Gnome and KDE desktop options are well polished to fit with the opensuse theme and environement, so either desktop is a great choice.
Pro Very stable
Stable, reliable, rock solid.
Pro Amazing choice for both newbies and power users
OpenSUSE is very easy in terms of installing packages, administration and customization, yet very powerful in the same. Every user should find his own piece of cake in this OS.
Pro Supports RPM packages
Popular format shared with distros like Fedora, RHEL, Scientific Linux, Mageia etc.
Pro Built-in drivers
Does the job needed and has the hardware drivers for the application built-in by the H/W supplier.
Pro Dedicated professional community
Directions on other desktop Linux's often force you to use GUI packages or have steps that introduce security issues.
OpenSUSE has a professional community and directions are usually geared toward GUI and CLI with similar steps.
Pro "Tumbleweed" Rolling Release
Regular and easy upgrades to stable and well tested software.
Pro Feature rich
It comes standard with a large number of pre-added applications that sort out your day-to-day use.
Pro YaST
Best administration and setup tool.
Pro One-Click install
Much better system then other distros for installing any package. It is as simple as clicking on one button and typing in your password. Adds a repo to your system keeping everything updated at the same time.
Pro Fast
Applications feel fast.
Pro Convenient package management with Zypper
Fast, reliable, powerful and almost impossible to leave a broken system.
The Yast interface will also give you access to a Zypper GUI if you are uncomfortable with the command line.
Pro Outstanding community support
OpenSUSE has a VERY active user community. Questions on forums are generally answered in minutes.
Pro Persistent changes
Changes you make in the configuration persist if you run from USB.
Pro Pretty fast to boot up
It was considerably fast to turn on when booting from cd.

Pro Modules
Standard tar archives plus some simple shell scripting produces modules that you can load dynamically into the OS for added apps and functionality.
Pro Modern desktop

Pro Small footprint
About 200mb, but with a full KDE4 environment and loads of useful apps.
Cons
Con Some clear differences from other Linux distros
This might be a systemd issue or OpenSUSE specific, but changing certain text files does not update things. They must be edited in YaST, or in /etc/sysconfig/
Con Old kernel by the Leap version
Kernel in Leap 42.3 is in version 4.4, that's pretty old.
Con Poor support for nVidia drivers in Tumbleweed
No native driver support and nouveau may be broken, especially for KDE, and not suitable for some GPUs.
Con Bloated and slow
Con Short lived distro
Every release lasts 18 months only before needing a major upgrade.
Con Updates
Not a huge problem, but Tumbleweed is better updated via the command line.
Con Massive ISO download
The base ISOs are over 4 gigs, so be prepared for a very long DL if you have slow internet. There's a network installer version, but that just delays the long DL.
Con Bad support to NTFS fotmat.
Con Limited community support
The community is fairly small, and there is no indication on the forums regarding when a issues will be solved.
Con Packman repository has to be added to have good software support
Con Startup takes a long time
Con Updates
Not a huge problem, but Tubleweed is better updated via the command line.
Con Complex permissions policy
Con Overly complicated HDD/SSD installation
While it has a nice layout Slax's lack of an installer tool like Tinycore's just can't be justified. It seems strange that it comes built in with programs that some users may not want, yet it doesn't have an easy way to install it. Due to its heavier use of RAM, built in software, and lack of an installer its hard to choose it over TC.
Con Works slowly on old computers
Con Infrequent releases
Since Slax is maintained by only one person, releases are not that frequent. So it may take a while to get bug fixes or new features once you start using it.
