Based on the U-tube video, it could be like the Fisher 1266, when it comes to air tests vs actual in-field performance. Ie.: On the 1266, you can get wickedly deep on air tests (18" or more on a quarter, for instance). But in the field, you hit a brick wall in all but the most mineral free soils. Or, heck, you can make a Minelab 4000 do that too, but to actually use it in the field for coins/relics, would drive you crazy. Ie.: TOO sensitive, and blaring off every staple, BB, etc....
The only way would be to actually try it over targets, in actual ground. Their ground test on that video is not convincing, because anyone can bury a target, in a clean stretch of ground, and "tune" the detector to get *just* that one target. Ie.: not realistic once you leave and start swinging elsewhere.