I've personally used Nightforce scopes on some DARPA XM3's. Great quality scope and it holds a great zero even when I was on a Osprey. The ospreys tend to rattle in flight if you have never been on one. My premier reticles scope on my M110 SASS is garbage compared to the Nightforce. One of the lenses moved itself while in an Osprey one time. For ruggedness, I'd go with a Nightforce because they beat the crap of out each scope before they sell them on the market. At the factory, each scope goes through about five stations and each station batters it against a desk or post about five times to test its ruggedness and durability. Otherwise, Schmidt & Bender is a great piece of glass as well. It's equal or better to the Nightforce. I've been using S&B for about 7 years now on my bolt actions, and I couldn't ask for a more clearer, reliable piece of glass. I am a big fan of both and stick to MIL/MIL because we are in a new century and modern technology is relying on the metric system more and more. It keeps your shots consistent as well as you.