Ryan G, nothing specific in the way of tests were done, but I went over several inch thick chunks of wood and it still registered small nails in a four inch thick piece.
I'll try to remember to do some more testing, then share the resulting info. So far, it seems more promising than using my Wizzard because, as I stated, it doesn't have to be recalibrated every time I turn it on.
AND, the battery suggest is a good one. I have about nine or so tools that use batteries. My Bosch level batteries went bad and I, literally, had to drill the last one or two out of the long tube. I thought I'd destroyed an expensive tool/toy, but it came back to life.
I'm going to have to change habits, since I've gone from using such things monthly to some of them being used once every five years (e.g., self leveling lasers and other lasers, etc.).