I have a simple use case. I want o copy some music. I have an 8Gb pen drive and my Music folder where each album is a directory inside the artist name directory. I select some artists. I select a couple of albums and dragn'drop them. Select some more, and copy again. The file manager almost freezes.
The problem is that Ubuntu tries to copy them simultaneously, instead of just queueing them. This parallel writing is extremely slow.
Yes, I could ctrl select every one and do just one dragn'drop action, but my experience is that I'd make a wrong click and undo all my selection.
I didn't think that it would be a problem in 2013.