Well right now in the town I live in there is a unique opportunity..They are literally tearing older houses down left, and right due to Hurricane Ike, and FEMA...So I have gotten to hit several sites, now don't get me wrong I have hauled Wheats, Rings, and tons of Clad from the 60's, Toys, Horse Shoes, Etc...I start off using the Ace with Sniper to Clean off the Top, then Switch over to the AT Pro with the 5x8 double d coil in pro mode..I found a couple of WWII Collar buttons in pro mode, but it will still ring up in Standard, I can tell no difference in penetration..I do however get less stability in pro.I also realize to find deep, there has to be deep..Perhaps its just me, or my expectations were too high...Could also be a problem with this machine..I have used it almost every day for at least a few minutes, and some times all day..I have used a lot of different types of detectors over the years, but this one has me bamboozled...I got it mainly because it could get wet, as yet it has not...Thanks for all your replies...