I have the pre WW11, uncoated f 1.5 Sonnar on a Contax 11, and the thing I notice manly is the difference in contrast with the images to more modern optics, I think the actual sharpness of the images are not much different, but what adds to the apparent sharpness is the increased contrast, something that lens manufacturers have discovered since.
These pictures of beautiful young girls have a lovely gentle contrast that is particularly appropriate for this sort of subject.