Is the Zeiss 28mm f/1.4 Otus Lens sharp? This page visually answers that question. Shown above are 100% crops from a lab-captured 28mm f/2.0 test image. Observe the contrast and resolution of these results.
Is the Zeiss 28mm f/1.4 Otus Lens set to 28mm f/2.0 sharper than the Zeiss Milvus 50mm f/1.4 Lens set to 50mm f/1.4? The image quality comparison above also answers that question. Switch between the results to see the sharpness differences between these lenses.