One thing I always worry about during email migrations is losing folder organization. Rebuilding mailbox structures manually after conversion can be extremely time-consuming.
I recently used DRS Softech PST Converter  on an older PST archive, and the software preserved the complete folder hierarchy along with email headers, timestamps, and attachments. After conversion, everything appeared in the same structure as the original mailbox.
For large business archives, preserving organizational structure is just as important as preserving the emails themselves, so this feature was particularly useful.