I thought the DFX was an impressive machine at first. I read up on it extensively before getting it, hung out at the forum, looked at the Dave Z program, read the book, and came up with a program of my own all before getting the machine. On the first day I had it I went to a spot that had turned up a lot of clad and a few silvers with my Garrett GTAx 750 and the DFX pulled a Barber dime at 8.5". I was shocked and awed, really. And I did well with it on a few hunts and then I went out with a couple of CZ buddies and when we all fired up the DFX went NUTS. I couldn't be within 25 feet of either of them and my hunt sucked while they were reaping all kinds of finds. After that day my machine had a max depth of 3 inches. So I got a brand new machine, which worked better but it lacked the depth of the original. I never saw another target over 6" after that. I hunted with it for 6 months and made the best of it but it lacked any consistent ID at over 5" depth and things like minnie balls, buttons, and deep silver coins were all over the place on the ID but with some imagination I was able to make it hunt but it was painful. Then one day I went in the woods with my CZ friends and they were pulling minnie balls at 8" to 12" deep right and left and I couldn't get a ONE to their 15 or so EACH. I tried hitting some of theirs before they dig them and even in pinpoint it wouldn't do it. It had to go. Bottom line is that from my experience and that of several I know from the forums, that machine can be very inconsistent from one to the next. Maybe a little TOO much going on in that black box???
That said, if my original DFX worked as good after the first week as it did on those first few hunts, I would still have it. Too bad it didn't.