In low mineralized ground, I see no reason why SF and a similarly weighted SMF wouldn't get about the same depth...low and behold, that's exactly what happens in my low mineralized ground

. Albeit SMF has notably better target ID accuracy. Then again, what about mid to high mineralized ground and salt ground? That's where SF seems to suffer greatly compared Multi-IQ and the like.
Speaking of target ID accuracy, I would like to have seen how deep the Nexus hit that silver half if the discrimination was turned up to just below the copper and silver range. If the signal disappeared at around the same depth as the Manticore (with the manticore showing a proper ID), then the Nexus wouldn't be any better for finding silver, unless someone is crazy enough to dig all lol...that's especially crazy if you're digging down to 22".
Apparently, it seems the Nexus depth is achieved because the recovery speed is extremely low. There might be a little more to it, but that slow recovery speed seems to be the fundamental factor in achieving that depth. As such, I would think if the SMF developers allowed for such a low recovery speed, the depth would be similar between the SMF and the Nexus.
Let's keep in mind that analog detectors just like the Nexus have been developed for decades. I doubt the Nexus is doing something special compared to all those previous SF analog detectors, other than a very low recovery speed. If that is true, then why didn't all those previous developers use a very low recovery speed to get massive depth? Perhaps because it comes at a massive performance hit in all other aspects? Perhaps target ID accuracy at that extreme depth is useless? Or perhaps developers of the modern SMF detectors should allow settings for "Negative Recovery Speed"? Meaning, recovery speed so slow that it will hit at that depth, but target ID accuracy is out of the question.