Kurt,
I've only been out with mine twice now so I'm no pro at it yet. But here is what I know.
The tone alert function is only good down to about 5-6 inches. Any deeper that that and it reverts back to the regular tone. This holds true for the mixed mode high tone as well. You can swing it faster with the tone alert for shallow target hunting.
However it gets GREAT depth if you use it as designed, which is as a slow sweep machine. The optimum sweep speed for depth is a 3 second, 4 foot sweep. Count it off until you can do it as it is hard to slow down that far. At least I find it hard
This is how I'm counting (oneonethousandtwoonethousandthreeonethousand) Turn Noise Cancel off. Turn Tracking Off. Sweep slow, and listen. 10" coins are easy for this one.
The Motion Discrimination mode goes deeper than the no-motion pinpoint mode.
I don't particularly like the Pinpoint mode as it is very limited. I can't adjust the squeal range out as far as I am accustomed to on other machines of this nature.
The best depth is obtained by turning Discrimination OFF, Noise Cancel OFF,. Tracking OFF. AC Sensitivity somewhere between 16 and 20. The meter still works with Discrimination OFF and for slow motion deep hunting this works great. The rolling intensity graphic display is excellent. Very helpful in target identification.
When searching for the best hunt frequency, turn Discrimination Off first, set SAT speed to 0 and then cycle thru the freq options until you get a good steady one. You may need it to barely pick up a target to hear the threshold. Its very important for deep hunts that you have a good steady freq selected. A improper freq can cut 3-4" off your depth.
Overall I find it excellent as a slow motion deep coin hunter with a moderate learning curve. However you will be disappointed if you can't adjust to the required slow sweep or were planning to use the tone alert to help with deeper targets as I initially was.
Hope that helps.
Mike