I own them both and don't think you can make a bad decision, but for even money would probably go atacr. Weight seems negligible to me. The only time I'm using the high end on the nx8 is when using it as a spotting scope. Nx8 eyebox hasn't been an issue for me personally. And 16x seems plenty...
I would highly recommend Greg and Shannon at Mineral Mountain Outfitters. They are top notch, do a great job, and the wilderness they hunt is full of elk. We did a 66 archery drop camp with them a few years ago - had a great time! PM me for details if you'd like.
Last year I went on a great fishing trip disguised as a moose hunt. I took an 8 weight and was glad to have it - windy conditions, 6+" flies, rio's wire tippet. Used a floating line. Caught most of the fish on Ehler's Gator Done (red/white), Big Fish Deceiver, Tomahawk Warpath (in some deeper...