+ 1. The first thing one hears about this lens is that it is extremely sharp. Fuzzy, unsharp shots are likely due to a bad lens or user error.
Agreed. When I first reviewed first shots taken after purchase, I laughed at how stupid sharp everything looked. The lens will expose any/all mistakes one makes, especially if one does not understand where to focus within wide angle scenes, bad technique, etc... Have owned the 70-200 f2.8; 24-105 f4 v1, 100-400 II, tamron 150-600; The 16-35 F4 IS was still the sharpest of all of them!