Awesome Ultra Wide Angle Zoom
Great for Landscapes and Architecture. Unbelievable low distortion for such a wide angle Zoom.
Autofocus can hesitate a little.
I wonder if the reason for the auto focus issues with Pentax lenses is also due to the actual model related to this and other Pentax lens. Also, spot metering should help to reduce the probability of focus drift. Going form 12 point to 5 point metering might also help out.