I am a new user and I freshly installed VirtualBox 5.1.4 in a Ubuntu 14.04 LTS machine to test Ubuntu 16.04.1 LTS before upgrading.
I would appreciate if anyone of you could suggest me what key features should be tested in the guest os in order to be fairly sure that the upgrade could be successful.
I ask forgiveness in case the topic was already discussed before and I did not notice it during my research.
The host operative system seems installed properly and so far I just tested video and audio rendition without significant issues, apart from a time lag between video and audio that I reported with ticket #15853.
My Ubuntu host installation is quite bare bone, because I mainly use the computer to browse the internet with firefox and to create Ruby on Rails applications with rvm, git, postgres, atom, terminal and gimp.
I do sometimes watch some movies in internet or with SMPlayer and listen to music for leisure.
I make use of Text Editor, LibreOffice and Calibre.
Other key applications I make use of, apart from VirtualBox, are k3b, Synaptic, Nemo and Skype.
I also installed a vpn. That's it.