Recommendations for pre-staging data:

(Make sure you have latest DFSR.EXE installed on all nodes before starting!)

• ROBOCOPY.EXE - works fine as long as you do not use /copyall or /copy:S. As long as the root of the replicated folder has exactly the same ACL (including inheritance bits) on both machines, using Robocopy without /copyall (or /copy:s) will work as expected and files will not be modified in any way.
• XCOPY.EXE - Xcopy with the /O switch will copy the ACL correctly and not modify the files in any way.

DFS-R initial sync no prestage:

DFS-R with Prestage: