Active Directory Cleanup Wizard Usage

In Exchange 2000/2003, what is the Active Directory Cleanup Wizard and what is it good for?
MSKB 270652 has the following information:
The Active Directory Account Cleanup Wizard is a utility designed to merge duplicate Microsoft Windows NT accounts that are created when multiple directories are migrated or upgraded to Active Directory. The Active Directory Account Cleanup Wizard searches Active Directory for duplicate Windows NT accounts, and then suggests merge operations that eliminate the duplicates. You can also verify the individual merge operations. Finally, the wizard merges various account types, their attributes, and their properties into a single user account. Removing duplicate accounts in Windows 2000 Active Directory can help improve performance of your Exchange 2000 servers.
The Active Directory Account Cleanup Wizard allows you to:

• Identify duplicate objects to be merged. You can have the wizard search Active Directory for possible duplicate Windows NT accounts, or you can manually select the duplicate accounts that you want to merge.
• Review and modify merge operations that the wizard has selected to perform before you merge the duplicate accounts.
• Export and import lists of accounts. This functionality gives you the flexibility to export a list of merge operations (pairs of duplicate accounts) into a .CSV file so you can import them back to the Active Directory Account Cleanup Wizard for further review. Then at a later time, you can run the merge process.
• Use command-line options to run the wizard. For additional information about command-line options, click the article number below to view the article in the Microsoft Knowledge Base:

Links

XADM: Possible Uses of the Active Directory Account Cleanup Wizard – 270652
XADM: ADClean Command Line Options – 270655