MDT with USMT

[gotenks98]

I wanted to know how safe and reliable this is when migrating users from say xp to windows 7 or vista to windows 7? I have alot of domain users and I was wondering how it works with domain profiles. With our current system what we do when we reimage a machine we delete the OU from the domain and create the computer again in AD. We do this so pcs will follow certain domain policies and for script purposes. I was wondering will I have to delete and create a new OU when doing this since the SSID for the newer installation would be different. Or does AD know that USMT with MDT is refreshing the pc? Also concerning domain profiles on the new pc usually for the part where I add users back to the pc I have to let them log in at least once to create the domain profile so I can start back manually copying their files and such. Can USMT create the profile on the new pc or does the person still need to log in once for this to work?