It will be very similar to a Plesk -> Plesk migration. All website content and emails will be migrated and in most cases the customer will just be able to update their DNS and continue as normal.
There might be some minor items/settings which can't be migrated. For example, with the cPanel migration we are about to release, it's not possible to migrate wildcard subdomains or Mailman mailing lists since they are not supported in Enhance.
