When comparing openSUSE Tumbleweed vs Debian Unstable, the Slant community recommends openSUSE Tumbleweed for most people. In the question“What are the best rolling release Linux distributions?” openSUSE Tumbleweed is ranked 5th while Debian Unstable is ranked 29th. The most important reason people chose openSUSE Tumbleweed is:
Tumbleweed is stable enough to use every day. Updates are OpenQA tested to ensure stability before being released for Tumbleweed. Bleeding edge untested software can be tried using OpenSUSE factory.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Stable
Tumbleweed is stable enough to use every day. Updates are OpenQA tested to ensure stability before being released for Tumbleweed. Bleeding edge untested software can be tried using OpenSUSE factory.
Pro Easy installation and cutting edge apps
Pro A large amount of software
Pro Tumbleweed + OpenSUSE Build Service
Pro Good selection of preinstalled applications
Pro User friendly + Good support
Active and friendly user community, updates come fast
Pro Great for Desktop use
It is great for your daily desktop Linux due it good balance of stability and recent packages - it is also recomended by the debian project as the distro you should choose for desktop systems.
Pro Up-to-date software
Cons
Con Little / no third-party support
Like it or not, most third parties don't want to deal with less-popular distros. So most of them only support Ubuntu LTS and those versions of RHEL/CentOS that are still supported.
Con Complex multimedia codecs and plugins installation
Con "Online Update" update in YaST control center only works in openSUSE Leap
Con Packman repository has to be added to have good software support
Con Slow and painful unfortunately, especially compared to other modern distros
Con Development version
Debian Unstable is intended as a development release, and as such is much more likely to break.
Con Not for users new to Linux
You need to know how to maintain Debian Unstable or you can easily bork your system. There isn't very much information available on how to maintain Debian Unstable either. I was fortunate enough to be involved in a now defunct Linux distribution where a forum member put together a how-to on how to upgrade Debian Stable to Debian Unstalble, as well as a separate forum where users could post tips or ask questions about Debian Unstable. One source I would recommend is the Siduction forums.