I got an idea that might help pinpointing with a DD coil. I got the Eurotek Pro with the DD coil and being not used to pinpointing with a DD I had to dig a little larger plug than I like, I did get better after digging a few targets. Here is my idea, get a piece of flat cardboard at least twice the size of your coil and draw a circle as big as you can on it, place a coin on a clean part of your lawn and put the piece of cardboard directly over the center of the coin (so the coin will be right in the middle of the circle but underneath the cardboard so you can't see it), now waive your coil over the cardboard and where you believe the pinpoint spot is put a dot with a marker,crayon,etc. Do this a number of times and it should give you an idea of where the sweet spot of the coil is and should improve pinpointing when out in a real hunt. Just a thought.