Oracle today released a 7.0 maintenance release which improves stability and fixes regressions. See the Changelog
I also use a version of Fedora running on VirtualBox for tests and rapid development.
Most use Linux on older hardware as a backup OS...
You can use Linux with specific non-default settings for good security of the operating system, but it does not make it invincible.
I don't know if VirtualBox solved the resize of the virtual partition - this was the last issue I encountered with this tool, but it is useful if you want to test something quickly.
