Well, if you’ve ever used the Robocopy GUI written by Microsoft’s Derk Benisch, it includes the ability to create Robocopy scripts which you can execute in parallel. (Plus the GUI is pretty cool.) ...
The GUI is fine if you're only moving a few files, but for larger and more complex migrations, this built-in Windows utility is the way to go. There are many ways to get a file from Point A to Point B ...