Nightforces are heavy and bulky, with only fair optics,
I think the optics on the NF scopes are quite good,
After going through four Swarovski z5 5-25X52 before I kept one, there is no way the Swarovski z5 is in the same league as the Nightforce 12-42X56 that I had. During the day all four of them are not as good as my 6500 for resolving detail. When I compared my 6500 side by side with my Nightforce, withboth set on 30X, by looking at leaves and twigs about 150-200 yards away I thought they were about the same. But at 521 yards with the Nightforce I could see the lines and spaces of my line chart with the scope set on 12X. The lines are about 1/4" black lines and white spaces. The Bushnell needed 15 1/2X while the Swarovski came up the rear needing 16 1/2X. There was about this same difference in low light performance, maybe more.
Maybe all four of the z5's were the worst Swarovski ever made and the Nightforse was the best one ever made. Does that explain all the z5's needing 25% more magnification to show the same detail at range? Could it be Swarovski folks really haven't had experience with Swarovski and Nightforce scopes after all?
Often I think of what Jim Carmichael told me: "Most gun writers do thier shooting with a typewriter." I think most internet posters echo what other internet poster post without having real world experience.
