Account Transfer with resyncronization
If you want to move many accounts (or a whole server) this can take some time. If you are wanting to keep the same IP(s) as well then the switch over needs to be for every domain at the same time so every account needs to be resynchronized pre switch otherwise you could lose many changes. The express transfer does not really solve this issue.
We have had to create our own migration scripts to copy configurations, accounts, databases to new server using rsync. This is particularly relevant now there are many centos 5 servers to migrate to centos 7. Perhaps the account transfer tool could include a resync tool. This would also be useful when an account needs testing on the new server before DNS is changed.