If you haven't run a super compact scope before, its difficult to explain, but without the generous eye box of the larger ATACR, it can be finicky above 6X, meaning if its on a rifle that has any recoil, likely youre going to have trouble staying on target unless youre running a bipod or off a barrier of some sort. Off hand shooting will be fine at lower magnification and 1x, but when you go to 6-8, it really needs to be steady, or slow fire. With the ATACR, movement isnt a big issue and you can shoot off hand fine with the magnification turned up, and still get back on target relatively easy. That isnt a problem with the NX8, thats just the inherent design of being ultra compact. The 2.5-10x24 is the same way, but it wasn't intended to compete with larger scopes like the 2.5-10x42 etc, it was meant as an ultra small scope for a light rifle, DMR or something that does some close range work, or sits on a bipod to take longer 500 meter shots at max. If you had a SBR, 16 inch gun, or even a 20 inch setup that spent a lot of time doing 50 yard stuff, but made some 200-400 yard shots against a barricade, the NX8 would be WONDERFUL...^ what do you see being the big difference to put the ATACR 1-8 on the scar 17 but not the NX8?
What im trying to say, without stirring the "well Nightforce needs to fix that" when it isnt a problem in the first place, is choose the scope that matches what you NEED, not the price point you can afford. If the proper scope isnt in your budget, either wait until you can afford it, or get something in your price point. The NX8 isnt a cheaper version of the ATACR like the PST is to the Razor, its a completely different scope with a completely different purpose, and I think a lot of people are missing that by assuming its somehow a competitor for the Razor.