I thought I'd be a little more clear as to exactly what I don't like about the QXT. I do wish there were more than 8 zones, or at least a way fine tune each one with perhaps a VDI # setting for the start and end of each. Lacking that, at least a way to assign high tones to specific number ranges would be nice. Again, lacking all that I would be happy with a simple VDI # displayed on the screen would be very helpful. I can live without this feature when coin hunting but it would make splitting hairs on rings and other lower conductivity targets like pulltabs much easier. The Sovereign GT is much the same in that most coins get lumped into the 180 VDI number, but as with the QXT there are ways to tell the differences in coins from both the audio and VDI, though I'm still learning that on the GT. Where the GT really shines is in the much higher resolution of targets below the 180 VDI #. It's large number range makes it possible to avoid a lot of junk targets, such as pulltabs falling within a specific number range (about 84% of them fall between 153-165), and still be able to (in theory) find a larger percentage of rings that do not. That's based on some statistical graphs a friend and I compiled with random test samples of round/square tabs and over 100 rings of all types.
There is an advantage to the QXT grouping targets in a larger area (like coins) over many other machines with higher resolution, being able to tell by VDI what type of coin it is. The main plus is that a really deep coin will still respond with a COIN response on the VDI. VDI (& in many cases audio) drift on machines with higher resolution can often cause you to question the target's worth. The audio is the telling factor as to if it really is a coin rather than a trash object. Whites are generaly known for the excellent/long audio response and the little telling traits of the audio that help to grade targets. I never did care for the short "beep and dig" type of response many machines give. While the Explorer gives excellent target information via it's multitones, the response is short and I find that harder to investigate. The GT has multitones like the Explorer but the audio response if more drawn out over the target, offering me more data like most Whites to pick through.
What I'd really like to do is reprogram the QXT's software to display a VDI #. I would guess this would be possible as I would think the software probably arrives at a target value and then decides which number range it falls into to then display that zone.
A variable tone assignment via the VDI would also be helpful. Being able to assign a high, low, or all metal (mixed mode) response to each of the 8 zones is a very powerful tool, but it would be nice to fine tune it in this fashion. After owning or using most of the machines on the market over the years tone ID is something I simply can not live without. It allows me to hunt with no discrimination and listen for any highs mixed in with the lows. That's the one feature I thought would have made the 6000 pro xl a perfect 10. I found myself having to watch the meter constantly while hunting in any kind of trash in order to see exactly what it was sounding off to. There's also a lag in the analog meter, much like the lag in detectors that are loaded with software, that makes response times slugish between targets.
Mainly for me I do prefer a computerized detector with an LCD display, but I don't care for machines that are so loaded with software that the audio and VDI seems almost detached from the coil's response. I like to hear and "feel" what the coil is passing over with as little intrusion from the electronics as possible. The QXT offers just enough software to tweak it out, yet still gives me the feel of the wheels touching the road, so to speak. I thought the Tesoro line would be much to my liking for that reason, but again I couldn't live without a tone ID or VDI response when I owned and used a Bandido II Umax for a while. The depth was good but, lacking tone ID, I found that I had to use discrimination and that cost me a good bit of depth.
If the QXT had VDI numbers, a variable notching system (or at least a variable tone assignment), and larger coils available in the 11 to 14" range it would be all I could ask for in a coin shooter. Since it doesn't have those features I'm forced to continue to search for the "perfect" machine for me. I'm hoping the GT will fill all those gaps in for me. It has variable tones based on conductivity, a variable notch and discrimination, a VDI meter to split hairs (yet seems much more functional in practice than the Explorer's dual number system), and of course a wide assortment of coils to fit my paticular needs. The only drawback I can thus far see with this machine is it's construction and weight. Far less user friendly than a Whites, but at least I can hip mount a GT...Unlike an Explorer.