One of the most stable actually. OpenSUSE Tumbleweed(rolling release) is what I run on my lapatop, and on my server I run OpenSUSE Leap(stable). That are based of SEL (SUSE Enterprise Linux) which is a competitor for RHEL. Its a little bit more complex than Ubuntu flavors, and it is RPM based, but it is quite marvelous and wildly developed.
OpenSuse is one of the leading edge stable operating systems, it's innovative with features like YaST, it has a desktop that is very familiar or similar to Windows 7 IMHO, with YaST you can do just about anything without seeing a CLI.
OpenSUSE is very much still tied heavily to novell and they work closely with microsoft. Its probably the MOST stable workstation distribution. Jump in get an opinion. YaST2 is a god send. You will know what I mean later.