What you can't do with expose but with workplace switcher is for example drag an image from a firefox window, hover over a different workspace in the switcher. This switches workspace to the application that is waiting for the dragged input image.
What you can't do with expose but with workplace switcher is for example drag an image from a firefox window, hover over a different workspace in the switcher. This switches workspace to the application that is waiting for the dragged input image.