Interesting parallel to the thread on experience qualifying one to be an expert.
I'd say I don't qualify to write a book:-) I cannot explain the behavioral changes of all the features of the V3i, particularly given the many coil choices and differences in earthen construct. I can't tell you why the V3i behaves better on the nail board when tuning 'salt' on as nails aren't close enough to ground that it seems it should have an impact. I'm about 6 years into the V3i and probably about 200 hrs/yr if i averaged it out. More early, and probably fewer now. Just last week I was playing w/ SAT to determine if/how much it might impact target response at depth and swing speed - jury's out. I'd probably register as highly qualified, but not expert.
I certainly know how to optimize gold settings for a playground like setting, but would generally lean toward the MX Sport w/ the 7" detech for that job. I'd defer to the V3i for park spaces when looking for gold....but all machines are tough when you have to dig turf for every positive signal. The V3i gives me enough additional info to select the targets i dig with some higher level of certainty, and that limits plugs. In the chips, i dig it all, so not worried about extra info. You cannot rely on gold jewelry to ring up like a shallow coin - solid VDI's in all directions and consistency across SMF responses as most gold has inconsistent shapes. Small gold will always hit harder on 22.5kHz with my setups, but large-ish gold and cross over and hit harder on 7.5kHz depending upon the shape and gold purity. Have NEVER seen 2.5kHz hit the hardest. One thing is certain. If you aren't digging foii and tabs, you are going to leave about 90% of gold in the ground. If you ignore all slightly negative signals, you may leave very small or deeper gold there for the next person.
On silver, i'd defer to the V3i for any moderate to deeper targets. It hits larger silver as expected to its maximum depth range in your given soil, but small silver can be deceiving. Dimes or smaller,
in western Oregon soil, will often ring up as high as silver halves or silver dollars when deeper than 5-6 inches. But, the SMF search display, and the polar plot easily distinguish them from deep iron or other undesirable targets. I've never dug a deep dime that didn't follow a pattern....and I've dug thousands of iffy targets that weren't deep silver dimes. Deep copper isn't as easy to distinguish, and I've called it deep iron before and had it turn out a deep penny. None of this holds water in ground w/ lots of trash...but if the target has a bit of separation, you get some clean hits, even on deep silver (6-9"), but cannot rely on the expected VDIs. After about 9", i think most dimes begin to look like iron and I haven't found a tell that distinguishes them from undesirable targets. Haven't found the 13" detech to provide any advantage over the stock 10"DD...but both do give me an additional 2-3 inches vs. any other smaller coil I use.
Nickels are funny. After a certain depth, they start acting like deep copper, with inconsistent VDI's on the higher end of the white's scale, occasionally pulling down into the nickel range,...but they rarely go negative til you reach the max depth. After that, i'm sure they start to sound like iron again. Only dug one nickel deeper than about 7", and that was a 9" 'V' that i am still wondering if i was fooled by a target on top of it...or whether i was actually hitting on it.
Still learning how to adjust filter frequencies to compensate for mineralization, EMI and swing speed. Still learning how to adjust recovery speed to compensate for coil choice and swing speed. So many things to tweak!
Does that qualify as a novel?
Zincoln