I got my M6 yesterday and went out for a couple hours with it, found a two wheat pennys 5 to 6 inches deep...I see this unit lacks a gain function (increasing sound on deep targets) but I find if you increase your sensitivity past 100 you'll get a gain function although somewhat staticy...The static or falsing doesn't bother me at all on this machine because its a totally different sound compared to a good hit, the static also makes a nice threshold.... I like it : )...I'm going to test this unit against my Etrac this weekend and report back