I've had my F75 for a week and have hunted a spot that I have absolutely pounded in the past (55 search hours and counting). Running in all metal mode really seems to make the coil "hot" or ultrasensitive, so that the machine works more like a divining rod than a detector. I'm picking up a lot more 'peripheral' signals and digging a lot more targets. The nice thing about all metal is that you still get the digital readout, which means I don't bother digging signals below 20-25. Great machine. Here's a 1921 City of San Diego chauffeur's badge that I picked up last night.