I do know this: with BW I find the difference to be not quite as apparent (adjust development, printing, etc) but with chromes I hugely can see a difference. One has a punch and the other looks dull, and when it's all said and done, I could compare the same scene with same conditions and film and clearly tell which one had better glass/coatings in relation to contrast. A side effect of a higher contrast lens is apparent sharpness too. Whether or not it's actually sharper isn't the issue, but the perceived sharpness because of the high contrast lens will definitely stand out.

EDIT: this is comparing two sets

First being the difference in chromes with a Minolta Hi-matic and my Pentax 50mm 1.4 -- clear and bright with the Pentax, much more subdued with the Minolta.

Second being when I went from a Fuji GW690 to my Mamiya 7II. Side by side on a light table, one doesn't take much observing to pick out which is which.