Klaus, something went wrong with the B&W pictures of the blurry diaphragm. The balls for 2.0 are smaller than for 2.8 and I do not get a picture for 4.0 at all. The LoCA 4.0 is also missing.
On the 8.0 image the balls in the corner are ellipses, stretching towards the corners. They are no longer round. I have never seen such behaviour before. Did you notice that?
When you discuss usability, I'sd like to remind on the "black cat in a coal cellar" situation. I am using portrait lenses as general purpose telephoto lenses in limited light with subject movement. If there is subject movement IBS and OIS do not help and one needs fast AF. Looking at the EXIF of the pictures I take, an f/2.8 telezoom would not serve me. Based on that I think your flak regarding the AF is fully justified.
