I started using VirtualBox (actively) few months back, my experience with it is excellent. Before using VirtualBox, I always had issues with installing new software on my computer because I did not want the new installation/updates to mess around with my working setups. VistualBox solved all of these issues. Now, I do all of my software testing/evaluations on virtual machines even I do all of my development (which require installations e.g. geonode) or host servers on virtual machines as well (read my blog ‘Access services hosted on guest from host using VirtualBox‘). Small tweaks here and there (like the one blow), VirtualBox is an excellent solution for developers as well.
If you have noticed, Virtual Box does not show fullscreen on virtual machines (VMs) and I hate to work on small screens (even I do not work on 15 inch and went to great lengths to get a 17 inch laptop). The fullscreen mode of VirtualBox is not what I am looking for, I need a solution which utilizes the available screen size, same goes for scalemode. Searched Google and found an answer on askubuntu (http://askubuntu.com/questions/104440/how-do-you-resize-the-standard-ubuntu-desktop-inside-of-virtualbox). To summarize, need to install following packages
sudo apt-get install virtualbox-guest-dkms virtualbox-guest-utils virtualbox-guest-x11
It worked on one of my VMs but then some how on my second VM the package virtualbox-guest-dkms (and others) could not be downloaded with error 404 Not Found. Frustrated, took the task to Synaptic Package manager. I search package virtualbox-guest-dkms and istalled it (that also installed virtualbox-guest-utils virtualbox-guest-x11). Restarted my VM and it worked.
Confused between apt-get and synaptic, I searched the difference and found this answer (http://askubuntu.com/questions/76/whats-the-difference-between-package-managers)
😦 the two sound same to me. I wonder what went wrong with apt-get
Note: This might not be the proper solution, but its what I experienced and it worked for me. Enjoy 🙂