Dave,
Secret my primary used to be the Explorer and I have seen hundreds upon hundreds of "Bravo's" for this machine. Thats probably one of the reasons why I bought the unit to begin with. However, with one simple test of holding an iron nail, "square-one" and a "coin", dime, quarter, penny, bullet, or whatever in the same hand. Take the machine and scan your hand. The Explorer would read it as a marginal signal while the C and V would hit it every time. Now think of soil conditions and think of the soil matrix. This would magnify the contents of your hand by an infinite number due to hot rocks, magnetite, frequencies that are in the ground and air, geomagnetic pull, and SOOOOOOOOOOOOOOOOOOOO many other variables- how well is that top of the line machine gonna produce in the real world? Sure it has done well for me and I am not cutting it at all. But, to go into sites where I have used this machine and found marginal items, to research the same site with the C and V, and start getting great results- a difference of night and day. I also own the Minelab Sov and haven't taken it out that much as again, I want results for my precious time. Both the C and V seem to produce where some of these other machines in the SAME, exact sites don't. I can't tell you the details as I am still figuring them out. Possibly the soil matrix changes and each machine is better suited for some types of hunting verse others. However, the C and V- do seem to consistently produce which is what I am looking for. As far as depth is concerned, its important but what is more important is being able to detect the item in the ground- some machines will go over the signal and not read it while others will hit it. Using the same test that I provided earlier, if you can hold an iron nail in your hand, clasped together with a coin, and be able to read that coin and not the nail, then you have a winner of a machine. If your machine produces a marginal signal- will you out in the field dig that signal? If it sounds iffy and all of the other signals that are in this one site are iron or produce a similar sound, will you dig? Or would you prefer that cleaner sound where you know that there is something good, and you know your site is old and the only thing in this site is gonna be from the time period of the artifacts you are looking for? Thats what I love about these machines. As if there is a good signal mixed in with all of the mineralized, ironized- "muck", I love that feeling of knowing I have found something good, instead of the thought, "Hmmm maybe this is a good signal, gee let me dig to China and possibly dig up something good" and maybe finding a great deep target or more than likely to unearth iron that has broken down through time and created a positive "halo" affect. Its all about getting results with the time we have to dig as most of us don't have that much time.