Within 3 minutes of pointing and image or drive towards VFC, you will be in the VM doing what you need to do to get the absolute most out of the investigation. So, with this in mind, why wouldn't you want to take advantage of the sandbox nature of a VM, especially with how quick you can access it!

Check out this specific example - a customer of ours used the VM to test the OS itself - WITH AMAZING RESULTS! 

Of course VFC and a virtual machine isn't limited to this, your possibilities are essentially endless!