You get less contrast with older lenses. You can use lenses like a petzval and force aberrations like swirls in the background. You can use a meniscus lens out of the barrel and get amazing soft, glowing highlights. You can use a rapid rectilinear and get much different tone rendition than a modern coated lens. If you shoot color, your going to get a different palette in the shot. There are plenty of reasons people use them and value them. And, probably, a lot of people are like me, and just value the historical idea of them. To be using a lens that has been is use for over 100 years has its own appeal.
Originally Posted by okto