I saw some portraits at polaroid gallery may be 5 or 6 years ago and damm , they were damm sharp on pn 55. I never saw sharper images in my life , they were african people on black ground and these images inscribed to my mind. I printed and developed 100 000 negatives with rodenstock when I was young and helping to fund my university expenses. It depends on all you do about printing. Rodenstock enlarger lennses are for blacks , I did not see better black than them.
Your suggestion is excellent , I have to figure out what is my best distance to image.
Thanks all ,