So yet again my planned Xen hyper-visor is on hold.

After converting my Server 2012 R2 from a generation 1 guest to a generation 2 successfully it has jumped up greatly in performance. Short version: Converted boot drive from MBR to GPT and added EFI boot, see here. FYI, you can do this from a Windows 8 install disc, but it must be a 32-bit disc, as gptgen is not 64-bit.
Also the fact I was able to get Ubuntu Server to install as a Gen 2 and get great performance.

Considering how nicely Windows took to not only being converted from physical to virtual into Hyper-V, it also took to moving from MBR/BIOS to GPT/UEFI, I don’t think Xen will get me any better performance, especially with the lack of specific official drivers for devices.

I’d like to use Xen in the future for Linux boxes since they love it, but I’m holding off until I can get another server for that.