I got a Falcon MD 20 used for spotting the gols I couldn't see very well. Figured I'd try it for pinpointing! Works good, and sensitive as (you know). I Met the owner of the company at a gold show, and he sent me a manual free of charge, and told me that they had made an upgrade, and if I sent it to them they'd do the upgrade free of charge. I told him I bought it secondhand and figured the warranty was up. He said it didn't matter to him. They did the upgrade and it is even more stable. Can't beat that for customer service and standing behind what they sell.
Oh, I regularly snoop flour gold in black sands with no effort.