I currently have both on hunting rifles. Leupold is clear and bright while the NXS is not as clear and bright. Both have 56mm lenses. The NF turrets are great. Leupold turrets are very good. Zerostop on the NF is solid as well as the Leupold. Both track as expected. The biggest difference is the illuminated reticle. Leupold is daylight visible. NF not as bright in the daylight. Leupold charges extra for the illumination to the tune of $450-$500. NF illumination is standard not a up charge. NF dependability is solid. Leupold 35mm tube versus a NF 30mm tube. May want to look at the NF ATACR 5-25. 34mm tube with better quality glass. Just my opinion.
Leupold turrets offer superior function and user experience. We've tested the 5x25 mk5 optically, and it is very good at that price point. I personally skip the weight of illumination, but I hunt out west.
I compared the NX8 2.5-20 to the Mark5 HD 3.6-18 and bought the Mk5. at full magnification the Mk5 edges were more clear and crisp to my eye, and the eye box was more forgiving. I just put a Mk5HD 5-25 on my Carbon Rival and love it. Tracking and zero stop are excellent.
Shot over a 1000 rounds 338 Lapua with Leupold 7-42 vx6. Turrets repaired once due to sticking. Switched to mk5 7-35 which is a definite upgrade. Have had no issues with it in first 400 rounds with braked 338 lapua. I would go atacr for range work but too heavy to hunt with
A 5.5-22 NXS was my first higher end, long range type scope a number of years ago. I’ve used it a lot and it’s been solid with no issues. Got a 3.6-18 Mark 5 about a year or a little more ago to put on a .25-06 AI intended for a long range hunting rig. Haven’t had a chance to shoot nearly as much with it, but it’s good so far. First or second focal is a big point between the 2. Glass handily goes to the Leupold in my opinion, although the NXS is plenty good. I very rarely use illumination, so didn’t get it on the Leupold. Both are big and heavy for a hunting rifle that gets carried much… I have gotten to much prefer first focal scopes for targets and hunting, so that would be the deal breaker for me. I got a solid deal on the Leupold, or I might have went with an NX8 instead. No bad choices between those 3, and there are several other good ones in the same general price range. Compare features / reticles and go with the one that checks the most boxes.