Usability: Hyper-V Server and Windows Server without a GUI will offer only Command Prompt and PowerShell as administration tools on the server console. Although you can connect from any other machine with a GUI, and perform maintenance and day-to-day operations, if connectivity is lost you should be familiarized with these tools, so you can at least recover the machine to an acceptable state where you can connect to it or even recover it.

Security: Windows Server with GUI is the primary choice for someone unfamiliar with Hyper-V or even Windows Server. That's because the GUI offers a more friendly interface, and, even if you are installing Hyper-V for the first time, you will be able to accomplish basic tasks, without much help. But the installation of a GUI comes with some cons too. One example is Internet Explorer (IE). Although...