In my review, I compare the 18-35 to the new 16-35mm f/4 VR. Distortion and vignetting series at 18/21/24/28/35mm are included as are very generous crops at those same focal lengths.
Users of Nikon cameras with cropped-frame DX sensors might find the 18-35 acceptable, because results in the central 2/3 area are good.
If you’re considering the 18-35 for a full-frame camera, I strongly advise reading my review first. Actually, I’d advise a strong sedative if you intend to employ it on a full-frame camera. Pick up any used Nikon prime in its range instead, like the Nikon 24/2 or 28/2 or the Voigtlander 20/3.5 Color Skopar.
Don’f confuse my distaste with price snobbery: there are many good new lenses that cost less than the $599 18-35, or even brand new ones, like the 35/2D and 28/2.8D and 24/2.8D, or my preference, the Zeiss 25mm f/2.8 Distagon.
See my initial comments below. I have nothing to add except that if this lens showed up gift-wrapped I’d promptly sell it.