As I understand VirtualBox Guest Additions can be installed via command line as:
apt-get install build-essential linux-headers-$(uname -r) virtualbox-guest-x11
Although there seems to be differences of opinion about what exactly is to be installed but my understanding is that these are the necessary and sufficient components. Different advice here, here, here, here, here and here and pretty much everywhere.
However this seem to install version 4.3.36.
This way Unity 3D is not supported which causes lagging. This can be verified by the following command:
Via the Oracle iso file version 5.1.18 is installed. With that Unity 3D works fine. I also understand that these packages are different as the iso is shipped by Oracle and the ones installed via command line are shipped by Ubuntu but in most threads they are treated as if they were the same.
So my questions:
What is the difference if any between these packages?
How can I install the latest version via command line? || How can I install a version that supports Unity 3D?
Currently using Ubuntu 14.04 and Virtual 5.1.18 but experienced this on many other setups as well.