Disclaimer, this grossly unscientific "test" is purely a backyard comparison of two lenses on the one body.
The images were all processed from NEF to JPEG with the same picture control parameters.

Nikon 14-24 compared to Tokina 16-28

Nikon at 14 and then 24 mm




Tokina at 16 and then 28mm




Here is where it gets interesting, first the Tokina at 16mm and then the Nikon at an indicated 16mm





Then the Nikon at varying apertures
2.8

5.6

8

11

16


Then the Tokina at the same apertures.
2.8

5.6

8

11

16