throughout my three different magnificas over the course of eight years the pre-ground mode is the least reliable function. You cannot afford to make any mistakes with this function or you will end up with terrible espresso shots or the machine will fail to recognize the pre-ground mode entirely. De longhi made this feature like a checkbox to indicate that you own a machine that can perform this function rather than one that they expect users to use daily. This is a better function on brands like jura that make it much easier to use their pre-ground mode.