Ease of setup
Creating virtual machines is often the most complex task you do with these programs, so how easy and flexible are they in this task? Any program will enable you to create a virtual disk and then boot from an ISO image as if it were an optical disc, from which you then run the standard installation process.
Beyond that, some of these make the process simpler, or give you more choices. How easy are they to use when creating a new virtual machine and how flexible are they? Before that, how easy are they to
