Hi I bought an f70 with f75 dd coil.It seems to be a little difficult to pinpoint but has a narrow band where it sees in the ground. I dont know how deep it goes for coins but it couldnt detect a nickel I buried flat at 8 inches.I was a bit disappointed at that. I did learn it has another mode for wet sandy beaches,kind of like a pi detector but nowhere near as deep.
I havent used it much lately.