So far still holding true to the Ten to Xen, and really like the "Easy Button" they have now for Thin Provisioned SR's. First boot takes a little longer then one would expect but afterwards it is about the same as 5.6. I am still disabling the following just because I had to with 5.6.
Disable ALL C-States
Power Management Disable or set to OS Control Mode
Power Management Performance if there are multiple places to configure.
Thanks for reading more to come on XenDesktop 5! As this project continues…