Re: nightforce ?
Depending on what caliber you are going to mount it on, either the Mil-Dot or the NP-R2 will serve you very well.
If I knew I was never going to shoot over 600 yards I would get the 15x I shoot regularly at 1k with a 10x. I like the 22x for 1k work but get by comfortably with the 10x.
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.