I just went through this decision process.
My use will be backpack hunting in CO and stand hunting in TX, so I wanted a scope that had good glass quality, tracked reliably, and was not an anchor.
ATACR: Solid glass quality and great durability, but weight knocked this one out of consideration for me.
NX8: I did not like the short design of the NX8, the eye box seemed to be limited to me on the 2.5-20, and the reticle was not usable on the lower magnification settings on the 4-32 F1 option.
NXS: I really liked the 5.5-22 F2. This one is quite durable, has solid glass quality, but was a little heavier than my ultimate choice.
Zeiss: The V6 3-18 F2 really works for me. The Schott glass quality beat the NXS, it has solid turret tracking, and the weight was exactly what I was looking for while hunting in the backcountry. I was a little concerned to not have an illuminated reticle, but not enough to give up the glass quality. This one is going on my new R Rbos 7mm RM that is currently being built.