Once I saw post in a forum in which some chap asked whether he should buy old glass (actually he mentioned a few models like Pancolar, Super-Takumar, etc.) or stick to the zoom kit lens he got with his brand new DSLR. And you know, opinions are like asses: everybody’s got one; there were all kinds of answers, but one fella made me smile telling the guy that both all those classic lenses and newer ones were better at taking pictures than we are photographers. That is and isn’t true.
To be fair, lenses formulated in and after the 1980’s beat hands down older lenses at key aspects like flare, contrast and resolving power. Coating tech may not look so glamourous as optical design, but the revolution came from there.