Consider the three questions in this blog before you commit to any Office 365 migration.
A data migration has many more factors to consider than simply the speed that the data can be migrated. Find out more in this blog.
Find out the costs associated with maintaining an on-premise Enterprise Vault legacy archive compared with migrating to Office 365.
Find out why it doesn't make sense to split Office 365 Onboarding and legacy archive migration into different projects.
Before making any investment doing a full scale migration, why not test the solution with a proof of concept with your users, your environment and...