Typical beep and dig detectorists to minimize bad finds will look for solid repeatable signals in both sweep directions of the coil. Then will rotate and look for solid repeatable signals in at least a few other directions, before digging. For your typical single freq machine (beep and dig) if they see jumpy numbers and non repeatable tones they walk away.
When i first used the NOX i used it that way too, and i came sooooooooo close to selling it because I did not see any reason to keep it, I might as well just use my F75 or At Max or Impact ETC.....
Now it is not a v3i like Wood said but never the less it is highly customizable, I would say it has a little over half as many tweaks as my V3i does, which is still a substantial amount of tweaks that can be made to the unit. I have set up custom tones on my Nox 800 to mimic my FBS machines.
Now the day i learned to use the Nox, I was at an early 1900's park that had a school house there at one time that was torn down. Loads of iron everywhere if you have iron audio turned on to hear it. This park is about a quarter of an acre very small. I went there with a friend who took another friend of ours the week before. He had a Nox 600 and found roughly around 20 old coins while my friend that took him used a beep and dig detector and maybe found one coin, not sure on that trip if it was one or none. I was invited the next trip and i hunted the place with ctx 17 inch coil and stock coil, Etrac with ultimate and stock coils, Impact stock coil, F75 stock coil. I also broke out my Nox 800 and found nothing. I was using it as a beep and dig typical machine. I had hunted about 3 hours and found nothing and neither had my friend. We knew others had hunted this place recently as well, because they did not cover up their holes very well. Frustrated while we were taking a break I asked my friend that brought me, just what did and how did our friend manage to find that many old coins last trip. He said our friend was digging iffy sketchy signals it looked like to him. I grabbed my Nox 800 and walked to where I had been hunting previously and where our other friend using the Nox 600 found most of his coins. In less than a minute I got a target that gave a sweet high tone mostly one way and the numbers were all over the place, but i was seeing glimpses of high 20's on the ID at times. As I checked the target in a several different directions as described above I kept hearing glimpses of the high tone with really jumpy numbers. Then I decided to use the horseshoe and i could hear the iron loud and clear, but still could also hear the glimpses of high tones and jumpy numbers.
I almost walked away to find my next target but remembered what my friend told me about what types of signals our other friend was digging to find all those old coins. I then decided what the heck I had not found anything all day so what would it hurt to try it. I buried my shovel (seven inches deep) and cut my plug and turned it over, then ran the nox over the plug and nothing. Then I checked the hole and was still getting the iffy high tone and jumpy numbers, but still seeing glimpses of high 20's every so often. So I stuck my garrett carrot in the hole and nothing. I dug another 3 inches and put that on the side of the hole and ran my pointer over it and sure enough it was in there. Turned out to be a barber dime at about 10 inches deep. I also found some iron nails in the hole.
Now my excitement was high. I used that technique to pull over 20 old coins in the next 2 hours. Did I get fooled by iron? I did a few times before I narrowed down the the technique and towards the end I dug no more iron at all. The friend I was with tried several machines that day and he pulled one merc dime with the Impact, and that was all he found. We went back a couple weeks later and I found over 20 more old coins using my new found technique while he found none this trip. My deepest was a barber quarter at 14 inches. If you get a tone you like on the Nox, if only iffy, stop and investigate thoroughly. If there is usually a one way and you see glimpses of numbers that match the tone somewhat as the number jump all over the place, dig. With practice you can master this technique where you will have a high percentage rate of good target recovery.
These targets are what I am digging in public places that others walk away from and with good reason using a single freq beep and dig detector. If I tried to use one of my beep and dig detectors this way (and I have) my junk recovery rate is super high. I run my iron bias at zero, and the guy that ran the 600 that one day uses 0 or 1. It takes practice and time but you can recover good targets with a high percentage rate.
I am not a video guy but I did make a short clip trying to show an iffy target i recovered at a spot I have pounded with every thing I have ever owned, and that is almost everything made. I take every machine there to see if i can find something missed with the others. Nox is only machine that is still pulling from this spot, even to this day. I still own and run V3i, Ctx, Etrac, F75, Deus , T2 special edition, Impact, Safari and cz3d and my trusty Nox 800.
https://youtu.be/v2lImonx8nY