Well this thread has gone a bit off track, so mods feel free to move the last few posts to the general metal detectors section.
I like knobs and switches too, but at the end of the day what wins me over is balance, performance and versatility. In these three areas, the Gold Racer beats the GMT hands down. In some recent tests I did in two spots with a range of VLF's, the GMT performed poorly. In the second spot which I thought was pretty mild ground I thought the GMT would shine, but it didn't even match up to an Xterra 705, which even through it's chattery threshold, it was pinging test targets clearly that the GMT couldn't make sense out of. Also had a Gold Bug 2 there, and in the Normal ground type and boost setting it is simply awesome, BUT try running it anywhere like that and it'll do your head in. Also in the warmer ground, the GB2 was going out of balance every few feet. This is where the auto/grab type ground balance of the GMT, 705 and Gold Racer leaves the GB2 for dead.
The Gold Racer had the best signal:noise ratio on a range of targets and on a range of soil types. Oh, in case anyone is wondering, all units had their stock 10x5 or 10x6" DD coils on, with the exception of the GB2 which is a concentric. I also much prefer the Zip-Zip sound of the GB2 or the Whip-Whip sound of the Gold Racer in the high tone. The GMT sounds like a quacking duck. Wonder if there's a trim pot inside where you could adjust the tone?