The manual says run 10 or 15 ok , Have you ever tried to disc out a small nail at a disc of 10 or 15 in disc mode? Steve on the garrett youtube instruction video HIMSELF was running a disc of 35 in all metal mode , he might need to read the manual. My ground is mild and is very easy on a detector....you have to remember the guys who wrote the manual I suppose are in texas and their settings might not work in your soil...My primary detector wont hit squat if you dont use a confident sweep speed or a tight wiggle with movement just like I do with the max in the video... Manuals are great for learning the features of a detector and a must... but test gardens with your own soil and the targets you will be searching for are a must and are where the rubber meets the road... The max has a feature in all metal that that the gold doesnt have , you can add disc in the all metal mode. I myself will never hunt in all metal mode I relic hunt in civil war and colonial sites and that feature is useless there unless you want to dig 10000 square nails .. take you a nail and lay it on the ground add a disc of 15 . What happened ? Does that make the manual wrong? Bury you a silver quarter at 10 inchs and try zero disc. 10 or 15 disc, 35 disc and then wide open and tell me which one hits it the best... Does that make the manual wrong? I would ad vise not to take my word for it , Johns word for it and in this case not even the manuals word for it. Conduct your own test and let us know the results. I don't know if you were talking about my swing speed in the video and making tiny passes , that how you isolate targets. I hunt thick iron sometimes machine gun iron and we are pretty good at it. I guess we learn tricks others don't know about , you cant hack around when your hunting that type stuff because your trying to isolate targets. If I made big sweeping swings in the test videos all that would do is show how trashy my test garden is with can slaw...Did I show something in the test results you didn't like? If so please tell me and I will do it again and use your suggestions on that particular test and see if it turns out different.. thanks