For STRICTLY nugget hunting, under typical Canadian conditions, NONE of those mentioned will compare to the GMT. With THREE ground balance modes. manual, automatic, and instantaneous "GRAB", it is more versatile than anything else. It has 1,000:1 ground balance resolution (compared to 15:1 with the GoldBug II) thus the GMT is extremely sensitive to small gold. The iron ID is second to none (closest comparison is the MXT). Now, for MULTI-PURPOSE use, the top ranker is the MXT, followed by the F-75, then the Lobo Supertraq. The same guy designed all three of those machines, the LST being the oldest technology, the F-75 being Fisher's intended competitiion to the MXT. As regards the GMT, there are two versions, the standard (rod) mount, as well as the rare, but still available chest or hip mount. (White's made 50 body mount GMT's earlier this year on special order). Hope this helps; HH Jim