Sensitivity (or gain and threshold)

When you are using a metal detector and use the Sensitivity control, do you prefer:
  • You can turn it all the way up without much noise or instability
  • You can make it all the way up at most sites before it gets noisy
I'm in the 2nd group, myself.  I like to know I'm close to unstable but just on the good side.  Some people prefer the detector "stable" all the way to the limit of the control.What do y'all think?