It was Charles Dickens who best summed up the state of photographic optics:
IT WAS the best of times, it was the worst of times, it was the age of wisdom, it was the age of foolishness, it was the epoch of belief, it was the epoch of incredulity, it was the season of Light, it was the season of Darkness, it was the spring of hope, it was the winter of despair, we had everything before us, we had nothing before us, we were all going direct to Heaven, we were all going direct the other way—in short, the period was so far like the present period, that some of its noisiest authorities insisted on its being received, for good or for evil, in the superlative degree of comparison only.
In my case, however, it is not a comparison between two, but among three.
In the days of film, the comparison of optics largely came down to how fast and how sharp. Low dispersion glass made sharper images, but the choice of film could easily negate any advantages brought by the glass. To be sure, Leica lenses gave images a different feel, but again—printing any image onto Kodak Polycontrast paper was the great equalizer. Without a good match between gear, film, paper, and presentation, the differences in optical quality were easily lost to the eye.
Similar problems exist with digital images: what I edit on my 30 inch, color corrected display is not what is likely to be seen on a Dell notebook display, or on a smartphone. And it will look different when it's printed on paper.