When I first got my Vaq, I ran it supertuned all the time. I realize now after spending much time with it that it was pointless.
RUNNING THE VAQUERO SUPERTUNED (SENS NEAR MAX, THRESH NEAR MAX) WILL PUT THE DISC WAY OUT.
When supertuned the detector becomes more sensitive to iron and trash. There are ways around this if you want to play with the knobs when you have a deep signal, BUT, I have found that the most effective way to to get the deep deep non-ferrous is to #1 balance the detector as perfecctly as possible #2 leave the thresh at a just audible level, sens hovering around 10 or above if possible and if the area is not too trashy, run it with the red button (All-metal) pushed in with the disc on foil. When you get the soft woot---woot check it slowly in disc. I find the All-metal very useful on this machine.
Hope this helps.