Don't know why my comment didn't post on YouTube so I'll put it here. I've noticed using my Nokta and now hearing yours that just like the AT pro the sounds tell it all..using the nokta there's a click before and after the tone going over bad targets like a bottle cap but going over a coin the tone is solid. I don't know of course if you tried rimming the target with the coil but I've found that if a target is in question rimming it shows the bad target by making the numbers jump around. I and a few others who have spoken of this here have only used this with the larger coil and not the mini DD but I'm going to check this out.
One thing to brag a bit about the nokta is during your video just how many other machines could have distinguished between the targets like when the coins were sitting directly on top of other metals..just doesn't happen.