To begin playing with the small coils in the thick iron sites I have here.....especially with a 5" coil coming for The Edge, & the 3.5" I'm gonna mess around with on the 1235/1270. Hopefully I can mark some targets & even compare signals. I'm looking forward to it. I have so many trashed homesites/cellar holes we have pounded with lots a different units, that when ya move the coil it's constant (-) numbers flashing on the LCD's. It's going to be fun seeing what unit/coil combo might fair best, or how much we might have missed. Maybe a ton, maybe not much at all? (But 1 masked Bust half dime or 1/2 Reale will make it all worth it!) 
Also, I haven't used an X-series unit in a while, & in my air-testing last night saw how you can tell a deep coin as more of a wisper. I had fun putting a square nail almost right against a nickel & the 3.5" hit that coin hard still. Only when the tip of the nail touched the nickle did that create a double beep. Of course it's snowing now so I can't try it out for real yet! 
HH, Bill
Also, I haven't used an X-series unit in a while, & in my air-testing last night saw how you can tell a deep coin as more of a wisper. I had fun putting a square nail almost right against a nickel & the 3.5" hit that coin hard still. Only when the tip of the nail touched the nickle did that create a double beep. Of course it's snowing now so I can't try it out for real yet! HH, Bill