Before going for any migration technique some of the things to be considered.
Is it supports direct migration to exchange server
Is it migrates all the email elements like mails, calendar, contacts etc.
Supported Exchange Server Versions.
Downtime.
Mailbox Size Limitations.
Is it supports public folder and archive mailbox migrations.
No Outlook Dependency.
If you want to avail all the above listed things in one tool , you need to check outEdbMails Exchange Migrationtool which has all the advanced features in it. It performs exchange migration process in no time without any data loss.