Generally speaking, a a lot quicker sweep will see much larger, further gold targets, but will often skip little shallow gold. A slower sweep will tend to get rid of sensitivity towards the deepest targets, but will discover little shallow gold easier. A further difficulty is the ground mineralization. Unless http://ostrza-avalon.phorum.pl/viewtopic.php?p=400535&sid=f6c30da1e6076d20e1be094e825193e3#400535