The Nightforce NXS line is more or less being replaced by the NX8 line up. The glass is the same, but its built around the different erector so you get a more compact scope with the newer/improved reticles. FFP on the NX8 would eliminate the NXS as a long range contender for me all together. If I was looking at a Nightforce in that price range, I would look at the NX8 first.
Leupold gets hyped up more on this forum than any other place I have seen. Not to say they are bad, but I have never been impressed by their offerings for the money. If you are looking at a straight comparison here, the Leupold is FFP with a bigger tube and bigger objective lens. Those three things in combination would make it preferable to me over the NXS but not the NX8.
Ultimately, I was looking at scopes in that same price range and went with a Vortex Razor HD II. While heavy, value for features they are hard to beat. I looked very closely at the NX8, but my research indicated it wasn't any better (in fact in some ways inferior) to the less expensive Vortex. I have been happy with my decision.