I have got this lens in Contax mount (chrome) as an advance b-day present, and had the chance to try it on both B&W and colour.
I'll let the results speak for themselves. Mom and Dad were the victims. Wide open:
Detail (100% scan)
The results stopped down are not surprising, but it's wide open that I'm floored. Not only is the depth of field as expected, but the bokeh and sharp to soft transitions are absolutely to die for, and the vignetting just perfect. I think this might even be better than the 105mm Nikkor.