I'm currently running pretty hot on the Nox, using field 2 and the standard coil. It isn't the best settings for very noisy and iron filled ground, but it is pretty good almost everywhere else
I usually run with sensitivity at 25 (no lower than 20) - multi tones or five tones - iron recovery set to 2 - can't really remember the other settings off hand, though I'm not really running a threshold.
I find it quite important to use the horseshoe to check for iron; I do find that there are good targets to be had at the same kind of numbers as iron; but things like coins give quite consistent signals from most directions and have a small pinpoint target.
I seem to dig loads of 1ps and 2ps at the moment; 1ps are 21-26 and 2ps are 27 to 31 (at least on multitones). Pound coins are 20-21, but so are 1/2 silver shilings. half silver 6ds are 17/18. new 50p is around 14, ring pulls are 12/13 - can slaw can be anything from 8 upwards - bottle caps 20/21 usually. Old pennies are 21-23, old half pennies from 17-20, although if they are uncorroded both of these are much higher (I had an uncorroded 1d that came up at 30).
hammered gold crown came up at 12 - thin gold ring (from testing) 9/10, heavier 18kt gold ring 19.
I'd recommend Dectecting NYC for understanding the Nox - he's done a lot of videos where he is learning the Nox and how to be better at finding things with it over about a year - and he's quite funny too (on Youtube).
Hope that helps!