Interesting thread.
I liked the 4-32x50 NX8 and was very unimpressed with the other two, but sample variation could be at play.
As a general observation, with Nightforce, I really like the ATACR scopes, but I am not real big on their lower end products.
I do think the AMG is a better scope than the NX8 in terms of image quality and it is very competitive with the ATACR.
NX8 4-32x50 is a very competent crossover design, but a lot of people who can put up with a bit more weight might be better served with one of LOW's 4.5-30x56 variants that cost a little less and work very well.
Another observation is that in all the years I have been talking about scopes, I have had good and bad things to say about nearly all of them, so I have had all sorts of brand fanboys yell at me for being unkind to their brand of choice.
In the scope world, Nightforce seems to have by far the most dedicated fanboys which is a testament to how effective their marketing is.
ILya