I ain't trying to start an argument here. But I actually agree with part of what both of you say. I, too, would recommend the small DD coil. I don't watch my TID numbers. I agree that Pure silver and copper will each give consistent signals (being of similar sizes and barring adjacent targets) And I seldom dig targets that are not consistent when sweeping over them repeatedly. Audio or TID. And they don't have to be consistent from all directions, (due to adjacent trash). But if I don't get audio consistency when sweeping over the target from the same direction repeatedly, I don't dig it. The difference in what we listen for and watch for can be boiled down to the hunt mode we chose. I typically hunt in all metal mode with multiple tones. As such, I can both hear the audio response and see the TID of all metal targets in the ground. When I hear the low grunt of a ferrous target, followed by a high tone, I know it might be an adjacent coin or simply a false tone from the outer edge of the coil. Going slowly over that spot from different directions will tell me how many ferrous targets there are, and where they are located. For example, (and you can try this at home), bury a few rusty nails in a circular pattern, a few inches farther apart than the diameter of the coil you will be using. Now sweep over them in all metal and listen to how many tones you get. You should be able to locate each nail. Now, switch to a Pattern that rejects those ferrous targets and sweep over them again. You might not hit a solid tone on any of the nails. But depending on how fast you're sweeping, I'd almost bet you will get at least one high tone from the "back side" of the first ferrous target. In fact, if you hover the coil between all three of the ferrous targets, you will likely get false high tone signals from just about any direction. And getting that "high tone" from the same place, over and over again, can cause you to dig a lot of empty holes. Again, it depends on how fast you are sweeping. That is why I like to hunt trashy areas in all metal and with a small DD coil. It gives me a tone for each target, rejected and accepted, as well as TID numbers for each. I know if there are multiple ferrous targets within the diameter of the coil, and how many. If there are, I can approach it from a different direction and determine if there might be a good target mixed in with the trash. To verify, I can go to Sizing Pinpoint and determine exactly where each target is. All of them. Ferrous and conductive. In a Pattern mode, you won't get tones on rejected targets. Instead, you get threshold nulling and the TID is blank. Like G4E, I like to hunt old farmsites. We just have different ways of doing it. I usually scout the place out with the 9-inch concentric at 3 kHz, followed by the 6-inch DD for those congested areas. When I use to hunt those trashy areas in a Pattern mode, I was constantly going back over choppy targets, checking to see if it was a false signal on a deep piece of iron, if I was sweeping too fast when I went over a rejected target, or I simply didn't get the coil centered over an accepted target. In my opinion, the reason folks using Pattern mode see their numbers bounce around is because rejected targets will skew the TID reading. Remember, rejected targets don't give a number. They give two dashed lines. And I also think the audio is not as "pure" due to the nulling of the threshold on those rejected targets. In all metal mode, multiple tones, there is no doubt what is under the coil as all metal objects have their own TID and audio tone. As such, falsing is minimized, TID is more consistent and audio tones are distinct. The only time I get falsing in all metal, multiple tone mode is when my GB or sensitivity is too high. JMHO HH Randy
........honestly on the sites I detect.....old homesites..........numbers are RARELY EVER CONSISTENT without jumping, when you have a ton of iron all over a yard, it is almost impossible to get a solid target signal. 
good write up...........next time put some paragraphs in there so it is easier on my eyes to read 