I've used both but only own a T6xi. I think the big advantage of the NX8 is it's smaller if you want the big magnification range. I prefer the turrets and MSR2 reticle of the Steiner. That's me. Glass is very good on both to my eyes. I don't have enough time behind the NX8 to split hairs against the Steiner and I think the bigger tube give the T6 give some advantage there. I have not had my rifle fall out of my truck or hammered any nails in with the Steiner yet but so far it tracks and stays zeroed under normal use after 1year. NF are well known for being excellent with holding zero after abuse. Steiner has way better scope caps included. These were the two final candidates I compared a year ago when I was looking. Now there is also the H6xi that may be appealing to you.