I've tested it (this is basically a writeup of my experiences) on my own machines and took the example output and configs from there. This still needs some technical review (technical terms, descriptions, etc.) and language love. Especially section 21.8.1. is a bit short right now.
Much more could be added (i.e. running on a shared storage do live-migrations), but I have not tested that yet. People can get started with the instructions provided here and we can add those points later.
A rendered version of the output can be found here: https://people.freebsd.org/~bcr/virtualization-host-xen.html