Stability. Every maintenance release is filled with special-cased 'fixes' that wind up breaking something else, calling for the next round of special-cased 'fi

Stability. Every maintenance release is filled with special-cased 'fixes' that wind up breaking something else, calling for the next round of special-cased 'fixes', ad infinitum. We've completely abandoned it for kvm and docker because we got tired of having our test platform broken with each patch release. Since we left virtualbox behind, all of our partners have had an easier time replicating our environment reliably.