I have a Cortes, which as everyone knows, has the same circuitry. I always read comments how these machines aren't deep, and you're better off with a beep and dig machine. But I think the secret of these machines is to keep the disc low or at 0 and use the TID to determine the target. What I found with my non-TID Tesoros is that when you turn the disc up, you loose depth. I found a lot of goodies with my Tejon, and my Golden, but not at the depths I'm finding with my Cortes. I get a lot of signals detecting like Richard is with his Deleon, and it takes a while to cover ground, but I'm finding an impressive amount of older coins between 8 and 10 inches down. Take a look at this picture. This school was built in the 20's and has never been detected as far as I can tell. I will also attach a picture of my favorite find so far. This is a silver dime found at 7".
In an environment with less trash, and a greater likelyhood of lost gold rings, I would dig more signals, but for now I'm pretty pleased with my results.
Dan