Hi Bill,
Let's see...... Honestly I don't run it "hot". When I'm hunting older properties, I am shooting for older coins. I have the gain set at 8. If more than that, it gets a bit noisy for me. I do have the SunRay Pro headphones and that helps me hear the small tiny little beeps for the deep coins. I also hunt in the relic mode with underneath trigger forward. Now when I'm hunting clad coins in the park or playgrounds, I do use the coin/jewelry mode. As for the gain, I keep it down to 6 since most clad coins and rings are only about 3-4 inches deep if that. That way there's less noise also. You still get a good signal that's easily heard when you come across a coin that's 5" deep . I would set the discrimination (dual control) at 2. This will let you get gold rings, pull-tabs and nickels too. If you don't want to get those items, put your disc. on 6-7. As for the threshold, turn it down to where you can hardly hear it. GO GO GO!!!!!!
I hope this helps. HH and good luck with your MXT Pro. You're going to love it more each time you use it.
Nancy