Depth all depends on how the coin is laying ,trash and soil conditions.You will always find coins at parks 5,6 ,7 inches. I focus on farm fields ,coins found there can be a little deeper.I tend to dig more iffy targets , the targets that ring only one time. I pinpoint the general area and listen for a week signal. On the 2500 hundred it would be called all metal mode.The 2500 hundred is a heavy machine and with 12.5 imagine coil it can get real heavy. The 12.5 covers a bigger area and can locate several targets at the same time under the coil making it a challenge, best used in open fields. What I found is buy the machine that you really think you want. If you settle for something else you'll end up buying your first choice several years down the road anyway.