I usually use the coin/jewelry mode with the VCO audio pinpoint.
I've found that the VDI number can change with deeper targets ~ but I guess it depends on the ground conditions too. I live in Oregon ~ my detector works great here ~ but it seemed to be different in Kansas when we were there on vacation. I can't put my finger on it ~ just wasn't the same as Oregon's ground.
Silver comes in great ~ coin or jewelry! The VDI number will go up or down depending on the size of the jewelry ~ but even a small silver ring comes in like a penny/dime.
Got dog tags? I'm looking for old dog tax tags and dog license tags! From any city, any county, and any state (prefer pre-1970) ~ firstname.lastname@example.org