Thanks for getting back to me regarding this
I know I have suggested a number of better methods including replication but he is adamant that is the way he want's to proceed with the migration (the guy is an idiot)
we do have very large pipes between datacenters but am just not sure that having a VM running from another site for a period of up to a week would be very good idea? as am sure the more that we move across the worse the performance will be on the VM?
I was really after a real world examples and what to test for when trailing this method