This is an old thread. My .02 cents.
I've used the Treasure Mate for a long, long time. The beauty of it is, it is tunable, and able to be ground balanced. You don't have to ground balance it for coins.
Some complaints may be that the knobs are always moved when putting in and out of the holster. My fix for that is to set it, and make note of the knob pointers. maybe 12 o'clock and 12 o'clock is a good setting. Or maybe 3 o'clock and 9 o'clock. Anyway, that's how I always use it for any given site.
Since Tesoro is closed, there is no more warranty work or even repair services. (I haven't found any repair services yet.) I have 2 of them. One failed on the adjustment knobs.
I was able to acquire the replacement pots, and should receive them in a few days. I am pretty sure I will repair this unit since I am an electronics genius.
I also hope everyone has good luck finding good stuff. Laters.