I've had this lens for about 10 years. She's clunky and heavy, and until I switched to Nikon I found the lens performed in the 'meh' field. Shot Pentax for 20+ years and I had the adapter for it, but the extra piece of glass just muddied the images.
First thing I did when the new Nikon arrived, I grabbed this lens and went outback to see what I could see. Both images shot @ F 1.4
Thanks for looking.