with the performance of the Deleon. Live up here on the West Coast of British Columbia ...quite a bit of mineral. Of no consequence to the Deleon. I does air test poor ...especially on our Canadian clad. But "nails it" when it's in the ground. I've found more of our $1.00 & $2.00 coins than with any other detector I've used.....in sites I've detected regularly!!! I have the feeling that manual ground balancing is over emphisized. Something is going on inside the Deleon that makes it fantastic. Also quite hot on gold rings....found a few small, and I mean small..... gold ladies 14K rings in fairly trashy ball fields......with the stock 8X9" coil!!! All I can say is ...this detector is really underated....a sleeper...poorly promoted..secret weapon. One of my friends who uses a Whites DFX just sold his unit...because when I lent him mine for a week he didn't want to put it down. Strange machine this DeLeon ???