The standard zoom has much merit, saving us changing lenses constantly and offering a versatile set of focal lengths. The focal length is a vital aspect and here the usefulness of have that ultra-wide 12mm (24mm-equivalent) cannot be underestimated.
Very good sharpness at wider apertures, Excellent flare control, Very low distortion, Well-controlled CA, Fairly priced, Very light and compact, Weather sealed, Beautifully made
Diffraction takes edge off sharpness at small apertures, f/4 aperture may not suit some applications