As you all know I love my old lenses, this lens was given to me by my Father In Law when I first got my K200d. I have loved it, a lot. You have to be careful with Chromatic Aberration in some situations but the bokeh is fabulous and it is really sharp when you nail the focus. Which is hard, as the Depth of Field at f2.5 is quite thin. If you ever get the chance to buy one, get it and never let it go. I would recommend a hood though, it does not deal with light on that big front element very well.
This is quite cropped, shot at f5.6, detail is better than my DA 55-300 at the same focal length.
Again cropped, and again really sharp!
Antelope playing by the TRAX station, was kinda wishing I had the 200mm f2.5 right at this point...
Wide open focusing on the first strap, I may have missed slightly to the rear, but it is still acceptable to me.