no AF, no auto diaphragm control and no lens data.
Aperture has to be controlled by the aperture ring and the viewfinder will always be stopped down.
However, novoflex do a make an adapter that lets you control the aperture on G lenses (the adapter has a little leaver that can adjust the position of the aperture leaver on the back of the lens)
So like acs says, it's only really any use for macro (although the dim viewfinder will get irritating), video, landscapes and still life.