Go ahead.
This lens did not give me very good impression. I used to think it has a poor MTF chart.
As my understanding of the MTF graph grew, my impression to it changed.
This lens does not perform well at long distance, but when it comes to 1 meter or other close distance, it is excellent.
It renders the skin tone much better than 85 1.4, 50 1.7, 50 1.4. These latter ones are astigmatic but S-planar is not. The skin tone is a bit like those from 100 2, 100 2.8 and 85 2.8 at 2.8 which are just nice. To me, I feel the skin tone of S-planar could be marginally better than my 85 1.2 but I certainly need more experience of my 85 1.2 in order to tell.
S-Planar has wonderful bokeh.
At the distance of 1m, you get beautiful head shoulder shoot with a natural perspective. With 50, you get nearer in order to get this and might get a strange perspective.
This photo was taken with S-Planar at f4. The original is a print 8X10. I photograph the print with my Sony 717 at f8. I must say looking at the original print is a lot better, but at least this web image can tell you about the perspective I am talking about and the great bokeh.