Jim, I can't speak to recent production Nikons but my sons, nephews and I have recent production Burris, Leupold and Sightron scopes. All three of those companies have no nonsense, no questions asked warranties and outstanding service. Over the last 4-5 years I've had reasons to return scopes to all three that either I or our 5 sons have damaged or bought used and wanted checked out.
All three companies did not care if we were the original purchasers or whether we had damaged them. The uniform response from all three was on the order of "The sooner you send it to us the sooner we'll fix it and send it back". Both Burris and Sightron used the same line "We warrant scopes, not buyers". I would not hesitate to recommend any of them.
With that said. Except for a few specialty long range precision scopes I now use Burris and Sightron scopes on all my personal center fire rifles, my muzzleloader and my slug rifle. The sons and nephews have a flock of Fullfield II scopes and mine is a Euro diamond which is in a far higher price range.
I have SI, SII and SII Big Sky Sightrons. In my mind and for my money the SI is a little better overall value than the VX-I Leupold and I like the adjustments better since the SI has 1/4 MOA click adjustments and the only VX-I scopes I've ever used had no clicks in the adjustment. The VX-I may have a little better glass but if it does I've not been able to see it.
The SII (3-9x42) is, to my eyes, better than the the Full field II or the VX-2 and the SII Big Sky (also a 3-9x42) is clearly better than my VX-III.
We've been very happy with the Burris Fullfield II line and I feel that they are almost the equal of, if not as good as, the VX-II scopes and a lower price point.
I think the Sightron scopes tend to have a more elevation and windage adjustment available than the others. The SII 3-9x42 has 80 MOA of adjustment and the SI has 70 MOA. My only bitch about the Sightron line is that they no longer make any low power SI, SII or SII Big Sky scopes and I really like scopes in the 1-5 to 2-7 range.
I hope some of this rambling helps.
Lance