Is the Canon EF-S 10-22mm f/3.5-4.5 USM Lens sharp? This page visually answers that question. Shown above are 100% crops from a lab-captured 10mm f/11.0 test image. Observe the contrast and resolution of these results.
Is the Canon EF-S 10-22mm f/3.5-4.5 USM Lens set to 10mm f/11.0 sharper than the Canon EF 17-40mm f/4L USM Lens set to 24mm f/4.0? The image quality comparison above also answers that question. Switch between the results to see the sharpness differences between these lenses.