Question : ADMT and sid mapping

Im migrating users from my win 2003 parent server domain to my win2008 (new domain tree) sub domain. I was going to use ADMT to do the miration of user accounts. Some people also incorporate sid mapping software while doing this. What is the benefit of using sid mapping software?

Also, does ADMT migrate GUID ?

Answer : ADMT and sid mapping

Sid mapping is used so that the permissions for the source account are work for the new target account.  You will also hear this referred to as security translation.  A better explanation here:  http://blogs.technet.com/b/deploymentguys/archive/2009/12/14/creating-a-sid-mapping-file-with-windows-powershell.aspx

The GUID is unique to the forest.

Thanks

Mike