Is the Nikon 14-24mm f/2.8G AF-S Nikkor Lens sharp? This page visually answers that question. Shown above are 100% crops from a lab-captured 16mm f/2.8 test image. Observe the contrast and resolution of these results.
Is the Nikon 14-24mm f/2.8G AF-S Nikkor Lens set to 16mm f/2.8 sharper than the Tamron 15-30mm f/2.8 Di VC USD Lens set to 16mm f/3.2? The image quality comparison above also answers that question. Switch between the results to see the sharpness differences between these lenses.