I echo the comments in your post, 'swingyDFX' man.
The Explorer II is a deep metal locator, but as for identifying those deeper items, then it does not do so with equitable finesse.
Even tho I prefer to search using Ferrous Audio for the thin hammered silver, here in the UK, even this mode gives erroneous responses on large iron....As for using the Visuals, be it SMART or VDI, at depths they are very misleading if you're anticipating text book indications. That is why the experienced users open up the Iron mask into the low -14 or -16. THEN they dig ANYTHING that that doesn't fall into the top left hand corner of the screen...or show 28Fe 30Con
You could coin a phrase (excuse the pun)...To be successful...
You must first be a metal detectorist and not a metal rejectorist.
The bare facts are, that the 1.5 kHz fundamental, finds the 'thicker' items better than other detectors. That is simply a fact of physics. Couple that with the larger than average search-head, then that is no more than should be expected. The hype about the extra harmonics has been greatly overstated by Minelab. That they exist, is true, but their beneficial contribution diminishes exponentially to a point of little better than surface scratching.
Have you seen a spectra-graph of the harmonic output ?
Do you understand that the significance of having to share the power available, exponentially, between the 27 harmonics? (+ 1 fundamental).
All this is not a criticism, but rather expose' of basic facts.
The EXPII's search-coil is the finest example of a true broad-band coil that I've ever dissected.
Their innovative circuitry is very good.
Their application of techniques that exist in other field of electronics, to that of metal detecting, is to be commended.
Finally, to return to the matter of reliably identifying deep targets.
Well, here is the common sense reality...especially for the EXP.
"IF THE TARGET CANNOT BE PINPOINTED EASILY, THEN NETHER CAN IT BE IDENTIFIED WITH ANY ACCURACY....Common sense really.....MattR.UK.