This is essentially the strategy I have employed in the past on my Mac using VirtualBox, although I don't remember the virtual machine image when I did it. So that is a nice addition that I'll definitely take advantage of in the future.
I would much rather have a clean virtual machine. A nice bonus is that in VirtualBox (and presumably other VM packages) I can restrict network access so that the server only communicates with the host machine and I am not opening up any external services to the net. Once I figure things out, I change the network settings and immediately have a live machine.