Is the Canon EF 24mm f/1.4L II USM Lens sharp? This page visually answers that question. Shown above are 100% crops from a lab-captured 24mm f/1.4 test image. Observe the contrast and resolution of these results.
Is the Canon EF 24mm f/1.4L II USM Lens set to 24mm f/1.4 sharper than the Canon EF 24mm f/1.4L USM Lens set to 24mm f/1.6? The image quality comparison above also answers that question. Switch between the results to see the sharpness differences between these lenses.