I sweep over the spot of my last recovery twice and then begin hunting again- best to recheck hole anyway-and this resets the g/b. Don't know about the targets being canceled out. I do know that whenever the ground drastically and suddenly changes in rare cases, I slow down the sweep to give the circuitry time and have picked up some targets in this rough scenario. It usually gives a little falsing when you hit an area like this. The tones really make my hunting easy as once I got used to them, the only time I looked at the screen was the nickel tone. Why? Well, if 18-20 it's usually a nickel- with an occasional nickel bouncing 20-22. If 22-26, it's likely a statab. Of course when I get serious in a likely area, I dig all solid hits in the tab/foil area- found some nice rings this way. Strangely, I got mine for the g/b and a little more depth and the tones and was surprised at some of the depths on coins. With all the features, I never saw any reason for notch, as I instantly knew the probable target by tones. And in one area I switched to 1 tone and the depth was unreal. I'm sure there are deeper machines, but this one amazes me for the price. My favorite tone is the mosquito-like high tone for silver-stops you in your tracks. Funny- doesn't sound that high without headphones, but with my Wally World $6 Koss headphones, it sounds really high. Finally, I hardly ever use the pinpoint function as I've been using detectors without it and the MX5 is so fast I can pinpoint it faster than using the function. Just love this detector!