I dumped it after realizing Xen does its damndest in preventing you from hiding VM attributes from Guest OSes.

Proxmox uses KVM, and is easy to configure a VM to make the guest think it's on bare metal.

In the proprietary software space, a LOT of things run badly or refuse to run, or license stupidity with a guest OS. So for me, spoofing bare metal is an essential part of running ilk like Windows and proprietary apps. And also, school remote testing garbage.