Is the Tamron 18-200mm f/3.5-6.3 XR Di II LD Macro Lens sharp? This page visually answers that question. Shown above are 100% crops from a lab-captured 150mm f/7.1 test image. Observe the contrast and resolution of these results.
Is the Tamron 18-200mm f/3.5-6.3 XR Di II LD Macro Lens set to 150mm f/7.1 sharper than the Tamron 18-270mm f/3.5-6.3 Di II VC LD Lens set to 270mm f/7.1? The image quality comparison above also answers that question. Switch between the results to see the sharpness differences between these lenses.