Well went out yesterday with the new F75. I like the way the F75 feels compared to the AT pro. The site was very, very trashy. Lots of nails which wasn't bad, big pieces of iron, but the amount of tins and tin pieces in this area was unreal. I dug tons of trash. I used the 5" dd coil. I messed around with the settings a little. My settings most of the time were sensitivity 60 to 80, tones 2F, disc at 6 or 7, and FA mode. Digging most anything above thirty. I messed around with 3 tone a couple times and even all metal for a short time. I had the dst-off @ 9.0, if the manual is still wrong. (so I read) unless they fixed that with the very recent new ones. I wonder if my F75 is not "sparky" or "hot". When I was testing in my house with the 5" coil I had sensitivity at 90 to 99 with no problems. I guess I was just prepared for lots of chatter from the unit at some point turning the sensitivity up. I don't know if that's a good or bad thing. So far I like it but am just getting started and have a lot to learn.