Normally its not a problem. But we have had cases where the people upstairs were overly active and you could hear that. As a result, we typically ask for a top floor room.
We didn't have a problem. We were in a second floor studio. We also didn't get any noise through the connecting door. As someone over on the DVC board suggested we put an extra pillow between the doors at the bottom of the door. Our studio was very quiet!