I'm considering the advantage of going with the more expensive Nightforce NXS in 12-42 versus the Nightforce Benchrest version also in 12-42 for about $400 less. Both look the same on paper as far as I can tell. Is it just that the NXS is built for more abuse in the field or are their more meaningful performance differences that would warrant the $400 difference? I plan on using the scope for long range target and prairie dog/woodchuck hunting.