I say this as a general but personal observation about some of Nikon lenses I own. I've noticed Nikon's professional (gold rim) lenses are exceptionally good and variances between "samples" or pieces are small. But it's consumer grade lenses are all over the place in terms of performance variances between samples. If you get a good one, it's great. If you don't.... it's not!

I once had a brand new lens in factory fresh box that came from an authorized dealer. I went through 5 and kept the best one but I still wasn't satisfied. So I sent it in under warranty complaining it's awfully soft wide open. (Yes, I manually focused) It came back with its front element replaced and auto-focus re-calibrated. Now it's pin sharp.

I mention this because it may be the reason why online reviews are all over the map.

By the way, this isn't unique to Nikon.... I also own a Tokina lens where it was purchased brand new, and service replaced the whole optical train under warranty!