Wow. Hard one. I have a soft spot for Steiner. I think they make a scope that is a cut above, and they do not get the recognition they deserve. I think those are pretty comparable scopes (the NXS line and the T5Xi line). You also have comparable MOA reticles. I personally find the MOAR to be a little more to my liking. The NXS will have a slight edge on durability, if you feel like throwing your optic down the driveway, but the T series from Steiner is solid. The M series meets the Nightforce NXS and ATACR in durability.
If it matters, I find the NXS holds its value better than Steiner, so if resale is ever a thought, that is worth considering. Warranty service will be similar. The Steiner is assembled in Colorado, so no going back to Germany.
I believe most of the T5Xi series is being discontinued, so that is something to consider about finding the Steiner if you want it, you might have to act now. Someone can correct me on that, but my Steiner dealer's sheet shows discontinued. We are dealers in both, and happy to talk to you about your choices. We only have the 1-5x in the T5Xi, but there are T6Xi options, which is probably a better scope over the NXS.
I would sleep on it, think about which reticle you will enjoy the most, as that is where you will spend your time. The turret clicks are good on both scopes. If I had to flip a coin, it would be for Nightforce, but not by much.
