QtQuick Control Slider doesn't have the same behavior as a native Slider.

1. User presses on the slider button, the slider button should have a pressed look to it.
2. User presses on the slider button, the button shouldn't move until the user starts dragging the button.
3. User presses on the slider bar (not on the button), the button should center under the mouse.
4. When user drags the slider button, the mouse should stay under the button and shouldn't drift while dragging it. Probably a scaling problem?

A good way to compare the two sliders is to open Interface Builder in Mac OS X and add a Cocoa slider.