NXS is a SFP design. Cronus is FFP. Do you have a strong preference whether between FFP or SFP reticles? Both are nice scopes. Cronus is a newer design, so it will likely have an edge overall in terms of optics. If you are looking in this price range, Delta Stryker HD may also be worth a look. I have both the 5-50x56 SFP and 4.5-30x56 FFP versions and they work very nicely.
ILya
www.darklordofoptics.com