Comment 1 for bug 749602

As the upstream maintainer of the Guest Additions I would like to relativise this somewhat. I certainly quite agree in the context that Felix made his comment in - since the development version of Ubuntu (currently Natty) is a moving target, Guest Additions from VirtualBox releases are unlikely to work well in it, whereas Felix keeps the Guest Additions package in Ubuntu up to date with not-yet-released fixes from upstream. For released versions of Ubuntu I would say that the difference is much smaller and that using the version which comes with VirtualBox can simplify things if the version you are using doesn't match the default Additions version in that Ubuntu release. (Note that I haven't actually investigated installing Additions for other versions of VirtualBox from repositories/ppas.) And I do take some care to make sure that installing the upstream version won't mess up your Ubuntu (or other GNU/Linux) system. I welcome reports of any cases where they do.