QDockWidget Docking Feedback is unusually slow when docking a floating QDockWidget on Mac

Lets consider two scenarios of docking a QDockWidget.

Case 1 - The QDockWidget is Docked

If you drag the QDockWidget and try to dock it in another area inside the QMainWindow then the docking feedback is acceptably fast.

Case 2 - The QDockWidget is Undocked

If you drag the QDockWidget and try to dock it inside any area within the QMainWindow then the docking feedback is significantly slower than "Case 1". In fact, it is so slow that if you don't hover in the same location then you won't get any feedback at all.

This behavior can be seen when using QT Designer 4.8.1 and it also happens in my program which is running QT 5.0.1