I hunt with both the NXS and the ATACR. They are not light, but neither is the game they bring down. I would rather haul a little weight in, to be able to see and hit so I have weight to haul out.
To have quality glass, strong tubes, and reliable tracking and turrets, it is going to equate to weight. In all honesty, I don't have long walks to stands, and I am not normally out west or chasing sheep. My longest walks might be 1-1.5 miles each way, but normally they are less than that so scope weight not that big of an issue. I also have a few heavy guns net of the scope weight. With that said, my light weight 6.5x284 still has a ACTAR 5x25x56 on it and it has been up high in the mountains of Colorado without issue.
I have found it interesting that people want an ultra light rifle/scope rig, then put a 10 round mag into the gun full of ammo and attach a bipod and can. Reminds me of the guys building a super light road bike, to add 6 water bottle holders to it and saddle bags.
If you are looking for an ultra light scope for a light weight mountain rig, there are quality scopes that are lighter than the NF. If the gun takes a tumble, will that lighter scope survive or hold zero, I don't know, but I have confidence in the NF.