Leaving stability issues aside, which are somewhat expected so soon after release date, OpenSUSE 11.4 is not a bad release. The KDE 4.6 implementation is stable and responsive, and all applications on board work well. Unfortunately, issues as critical as not being able to install RPMs, having popular applications not running successfully, or missing hardware support when it actually worked on previous versions, may become show stoppers for standard (non-expert) users.
If you like OpenSUSE, I would suggest waiting a few months before downloading/installing. I think many fixes should already be on their way to hopefully provide its great foundation with some much needed reliability.