I used the F70 for about 6 months. It is awesome. I am adjusting to and learning the F75 LTD now. With the F70 I have found IH pennies, wheatbacks, Buffalo nickles, reg 5 cent, V nickles, mercury/rosie and barber dimes. Washington quarter (clad and silver), Kennedy half, 1000 pasos coin, commemoritive dollors, large cents, civil war tokens, rings (mostly silver) jewelry, etc. Ive been lucky to find some of the large cents at 2 and 4 inches inches but also did find one at about 10" I have got silver quarters at 8 inches, and barbers at at least 8. So many variables like tunning, soil content, soil moisture, and many more can affect the depth detection. I put in a lot of hours. The 70 is a very good machine