Always Copy, Never Move! There are those who say moving is okay within the same folder/drive, but odd things can happen even doing that!

One example being incomplete copies. Now you have two folders neither of which is definitive and that can lead to problems if you're not careful. You also can't compare the two folders afterward to make sure you got a perfect xfer.

Yep, I went from using Teracopy to using Robocopy for everything. I like its error handling and reporting. Robomirror is a handy GUI front end if you frequently do the same sort of operations.