For me, there would be two questions to answer:
#1. Does the size and weight of the 3.5-15x50 matter to me vs the compact?
#2. Do I get any practical utility out of a 2.5x bottom end relative to a 3.5x bottom end?
If the answer to both is "no" go with the higher mag scope. You can turn it down to 10x if you prefer. You can't turn the 10x up to 15....
Looks like you are the only one interested in my threads.
If 600 yds is the max or mighty close to it...there cant be anymore than 10-12 brands that will do as good or better ( remember the distance) for LOTS LESS $$$$
Which scope would perform the best on a .300 Win Mag for shots out west 600 yards and under- Nightforce 3.5-15X50 or the Nightforce NXS Compact 2.5-10x42?