not using the test facility only planned migration.
What is slow? When you do a planned migration it syncs the disks a couple of times. After the unmound at the A site it will sync, aftherworths its going to rescan the HBA's on site B. I've got arround 20 ESXi hosts in that site. It rescannes 2 times. So a planned migration is easily 30 minutes plus.
Gracefull shutdown of VM's can take up to 15 minutes at our site (extended de default time-out)
In the screenshot a planned migration test from 1 VM on a 600GB datastore.
Works like a charm