When it comes to depth the density of the dirt seems to be a factor. I found a spoon that was vertical in riverbank sand over 400mm deep and the signal screamed. The horizontal profile was not all that big. I have only used my new (second-hand purchase) SDC once and this was at Hill End. I didn't detect gold but found more wire and nails than a hardware store and more horseshoes than the Melbourne Cup. Some of the nails and wire were quite small and deep but I was impressed with the SDC's ability to find targets. I know it was designed to find small gold but it will clearly find the bigger ones as well. Sure it is not a GPX or GPZ, but when you consider price, folded size and detecting ability, it's a winner.