<p>The 14-24 2.8G is considered the sharpest wide zoom of all, sharper even than most prime wides. Pro Canon shooters buy adapters so they can shoot with this lens. You may want to do a proper test, and look into a fine focus adjustment for yours if needed. The Zeiss wides may possibly be a line or two sharper on lab tests (questionable though), but lack autofocus and lack zoom. Do what works best for you, but be sure the 14-24 is not up to spec before replacing.</p>