Hi There,
We use exmerge for the following:
Email migrations: for the most part we would rather emerge rather than co-exist when acquiring new users,etc...
Archival uses - e.g. when a user leaves a company dump a copy via exmerge then to DVD for HR,etc...
Mailbox moves over slow wan links: e.g. I recently had a issue where I had to move a 5GB mailbox over a slow WAN link. Try as I might I was not able to do a regular mailbox move so I exmerged the majority of the mailbox to a pst, moved the smaller mailbox & couriered the PST to the remote site who then imported it locally.
Supporting Unicode is Exmerge would be the single best feature you could add - cheers.