Aside from the 1/8 MOA clicks on the BR and 1/4 MOA on the NXS, the NXS also has a side focus knob instead of the objective bell adjustment that is found on the BR. Other then that, it is mostly shape and cosmetics. Some have claimed the NXS is more "bomb proof". I do not know if this is true or just a rumor. The BR series also allows you to more easily adjust the brightness on the illuminated reticle. The NXS is either on or off. If you want it brighter or dimmer, you have to unscrew the cap and change it in there. I have owned and used both and love(d) em all. Some I still have and some I dont.
Long range shooting is a process that ends with a result. Once you start to focus on the result (how bad your last shot was, how big the group is going to be, what your buck will score, what your match score is, what place you are in...) then you loose the capacity to focus on the process.