Short answer is that I have the AT Pro and Nox 800 and plan on continuing using both. I had both of them out a few days ago at a permission. No dust collection.
I've cleared out some sites first with the AT Pro and did not find anything significant with the Nox afterwards. Yet other places I've put in hours on the AT Pro and came through with the Nox and found handfuls of more finds. So, it depends on the conditions of the site, what's in the ground, and how handy you are with the AT Pro in Pro Zero mode. I know the Nox can detect targets under certain conditions the ATP misses, but in most cases it's the difference of squeezing out a few more goodies.
That post I had a few days ago from the 1890's vacant lot was about 8 hours of the AT Pro using the standard and the 5x8 coils and then about 4 hours with the Nox using the standard coil. Heavy, heavy, iron. I never found anything significant in that few hours with the Nox. I cleaned my own yard out with the AT Pro--a dozen silver, 30+ wheats, and tons of other goodies--and I haven't found much else with the Nox. Maybe I would have cleared out that dirt faster with the Nox to begin with and dug less junk. Maybe not.
Yes, in other cases, it could mean a much bigger difference. In one large area of one of my permissions the AT pro was completely overwhelmed by the thousands of pull tabs in the dirt. At first I thought it was EMI, but it wasn't. All it could do was give jumpy numbers and an occasional beep. I went back over that area with the Nox and was immediately popping coins. No problem.
On the other hand, last Friday I spent a few HOURS going over a 40x40 area with the Nox and pulled a bunch of coins until I thought it was pretty well cleaned out. I went back over it with the AT Pro and found a few more, including some deep coins. Perhaps I would have found them with the Nox if I had kept swinging it. Perhaps not.
In other words, put the time in with the AT Pro, especially on Pro Zero mode, and you'll find lots and lots of goodies. I've found plenty of small, deep objects with the ATPro. It's proven over and over again.
I like the backlight and screen size on the Nox, I really like the ability to change the tone volume and pitch, I find the Nox tones much easier on my ears over long periods of detecting, I like how much I can customize recovery speed and iron bias to certain conditions, I'm certain the Nox resets faster, and I like knowing I can take it to the beach with no issues.
I don't like the Nox's compression of VDI in the higher conductors. I get pennies that ring up like dimes and quarters and quarters that ring up like dimes and pennies. I don't do it often, but I can cherry pick dimes and/or quarters with the AT Pro and call it 90% of the time. With the Nox I'm still digging some pennies when I think I might have a dime or even quarter. Yet, nickels practically jump out of the ground and into my pocket with the Nox.
