Really impressive lens
I have the version for SONY and its ability to focus up close and provide 1:1 magnification opens up new creative horizons. It can produce images that cannot be achieved with other lenses.
The SHIFT function (on the vertical axis) is also very useful for correcting perspective (great for buildings).
Sturdy metal construction and very sharp in the center even at wide open. The edges follow with a little stop down.
Overall, an exceptional lens as a landscape lens with unique features (macro+shift)