Is the Tamron SP AF 17-50mm f/2.8 XR Di II LD IF Lens sharp? This page visually answers that question. Shown above are 100% crops from a lab-captured 17mm f/5.6 test image. Observe the contrast and resolution of these results.
Is the Tamron SP AF 17-50mm f/2.8 XR Di II LD IF Lens set to 17mm f/5.6 sharper than the Tamron 16-300mm f/3.5-6.3 Di II VC PZD Macro Lens set to 16mm f/3.5? The image quality comparison above also answers that question. Switch between the results to see the sharpness differences between these lenses.