I started several years ago with the 85 f/1.8D then went with the 85 f/1.4D. I found it better for bokeh and over IQ. I then went to the Sigma f/1.4 and eventually sold the Nikkor. I prefer the Sigma's sharpness, bokeh and overall IQ. This is my primary portrait lens for individual head and shoulder shots.
As the Sigma 50mm 1.4 is favored by many over the 50mm Nikkors, the same holds true for the 85mm.
If you are not interested in non-Nikon lenses, I still think you'd prefer the 1.4. Perhaps you can rent or borrow one to test.