I was in a similar situation when looking for a dry sand machine, I wanted one with somewhat high operating frequency so it is sensitive to smaller gold (earring backs, pencil lead thick gold chains, etc.), but also wanted deep. It was between the AT Gold, Tejon, Gold Bug Pro, and Vista Gold.
After a ton of research, the only 2 that seemed to have the sensitivity and the amazing depth, were the Tejon and the Vista Gold. I went with the Tejon and I love it, but damn that Vista Gold looks like a beast. AT Gold would have been cool too with the screen and water resistant... but doesn't seem especially deep.
My vote is for Tejon or Vista Gold. Both run at pretty high frequency (17.5khz and 25khz respectively), but also run super hot to maintain amazing depth on larger objects.
After a ton of research, the only 2 that seemed to have the sensitivity and the amazing depth, were the Tejon and the Vista Gold. I went with the Tejon and I love it, but damn that Vista Gold looks like a beast. AT Gold would have been cool too with the screen and water resistant... but doesn't seem especially deep.
My vote is for Tejon or Vista Gold. Both run at pretty high frequency (17.5khz and 25khz respectively), but also run super hot to maintain amazing depth on larger objects.