So here's my official review and opinion on the Gordon High Precision Metal Detector:
It does what it's supposed to do pretty well or so it seems. The coil is concentric, about 9.5" so it gets good depth at high sensitivity, I find larger objects at 12", namely the rusty old utilities that are going to require replacing so that was actually something worth discovering. At lower sensitivity it detects shallower of course and the VDI appears to be pretty consistent, it reliably picks out different types of metal at the lower settings. At high settings it iron falses consistently on deep, rusty iron, so much so that I can reliably recognize deep iron when I find it, from what I've read this is not an uncommon thing across many machines so it's whatever. VDI scale is 1-100 with mid range tones representing the bulk of coinage pretty solidly, trash will give various VDIs depending on size and composition but generally it picks out good targets fairly well. It's pinpointer function is fairly accurate to within a couple inches, often spot on, on deeper targets you need to raise the coil a bit to get a good pinpoint is what I've observed. The property I'm experimenting on is riddled with iron but after doing some shallow clearing things have improved a bit. I still have a lot of ground to cover so I have plenty of time to get better at using it.
My general view? I'm glad I didn't invest in a more expensive unit, I find myself unearthing a lot of meaningless garbage giving good tones, aluminum, plumbing pieces and less describables that have similar conductivity into coins. I've experimented with the settings on it quite a bit and I'd say it's not bad honestly but it may not be the right fit for me. I'm not giving up on it just yet by any means but compared to using just a pinpointer it's kind of a pain. The best finds I've made have actually been with just the pinpointer and I think there's a few reasons why.
The minelab pro find 40 is an artifact/relic hound, using it I dig up a LOT less minor trash and I find big, far more interesting objects, ones I can date and even restore. Likewise I can get it into narrow and overgrown spots or close to metal fences without having problems. With the pinpointer alone I typically dig holes not deeper than 4" on solid targets which is nice and digging less on trash saves time. I guess the trade off is just that, you don't get the depth on small targets but the truth is that most of these small targets aren't worth digging on to begin with or at least not by my estimation. Yeah, there might be a coin 5" down but stopping to deep excavate every few feet is pretty tedious regardless of target ID and it is time consuming. I'm generally more interested in larger objects and relics, coins are semi interesting but not really what I'm after to begin with. Getting a copper signal on a bb buried 5"+ down is a royal pain for me to be excavating and certainly impractical in any field exploration. Size, mobility and capacity for discretion matter a lot to me too especially the way I gear up. I like to be able to just pull it off my belt and spot check an area with high probability of holding cool stuff. Humping in a full sized detector, setting it up and then going over an area is a big investment of time especially when I can locate relics faster using just my eyes, spade and pinpointer. It's a lot honestly. I do better without the big boy lol. Less time on small trash targets and more time on large objects I can do something with. So I guess my conclusion based on my experience thus far is that the Gordon is a decent detector at the entry level, it does what one would expect it to do and the sensitivity is pretty good all around, VDI is generally reliable and it's other little features are cool. I'm not disappointed but I don't think it'll ever leave the property, it's just not the right tool for the places I'm looking in or the way i search. We tend to hit dump sites where there's tons of metal in the ground, stopping to dig 4-5" every good signal will result in a large bag of trash items and the degree of masking would be off the charts. If I'm detecting I need a small coil, a real small coil so I can lock onto just one target in a sea of trash, the pinpointer can navigate the spaces where the bigger coil would be having kittens and for me that's actually the optimal choice. The Gordon was worth the money, it's really not a bad machine, just not right for me. I do like harbor freight products overall and this detector is no exception honestly. I'll just keep fooling with it for amusement, who knows, maybe it'll find something of value around the property that the pinpointer missed!