I've been using d2 for the past 8 days, and am very pleased with the results, but I am going to try d1 for a while now. Used d3 at first, but like d2 better. d1 appears (according to manual) to offer a bit more information. I'm very happy with the machine so far, and with the DD coil have recovered many coins in an area where I've used other detectors, many of them deep and most of them near other signals (trash). The soil is a killer, as it is an area which has been top-dressed with soils of diffferent types, which creates a matrix which makes it difficult for detectors to identify coins as well as they might ordinarily, in soil of one type. The Omega seems to handle it ok, but it too varies in its VDI...however, once you make allowances and are prepared to check out "possibles" as well as "probables", the coins just roll in. On my second trip there, I took a longer screwdriver with me, as the 6" I had been using was not long enough. It is an area where I cant dig holes, so am confined to probing and then prising out the target. Have not found any rings yet, but am ever hopeful.