...it would help you greatly to spend time hunting with somebody who has had success with your particular machine, whether it's the E-Trac, SE, Vision or whatever.
i've read all your posts. it's obvious that air-testing your machine is not producing the real-world results you desire.
it could take you months in the field to get a handle on your detector without a knowledgeable hunting partner, but that's how i learned.
and whenever i get skunked, i still thank my detector for getting me out of the house and showing me a good time.
i'd hate for you to give up or come away with a negative opinion without exploring all your options. best of luck to you.