Spoiler alert: there isn't any universal ‘finest metal detector for gold’. (Although the GPZ 7000 is close for the people of you who can pay for a detector that’s exactly the same rate as a car). Minelab’s GPX 6000 metal detector is developed by the whole world chief in gold https://archives.profsurv.com/forum/Professional-Surveyor-Magazine-Discussion/Education/-151479.aspx