If source and destination were all on the same hard drive, the move operation would be the quick one. Since it's just updating the directory location of the file instead of actually data-transferring the contents of the file.

For different hard drives, I would think they'd be about the same speed, with move being only slightly longer than copy (deleting each source file after each move should be quick compared to the move itself).

Anyway. The reason I thought of this is because a similar operation is the only way I can manage my iPhone photos. Iphones split all their files up into a bunch of randomly-named subdirectories, and the only way I can see a plain list of all my photos is to use that search box and type in *.jpg. If I want to make a backup of all the photos, I do that and then reconcile.