I just wish there was a bit more people testing CoreOS on bare metal with PXE. There are pretty decent docs on it:

https://coreos.com/docs/running-coreos/bare-metal/booting-wi...

http://coreos.com/blog/boot-on-bare-metal-with-pxe/

But I've not heard a lot from people with clusters of them. Perhaps I'll have to snag a small cluster of lab boxes and give it a go myself!