Finally read this article. It's a bunch of hooey. The examples shown don't demonstrate anything.
I love modern lenses for their accuracy, resolution, lack of flare and CA, and their clean imaging properties. I've not seen a modern lens yet that made my images seem flat due to its design—only things that cause that are my poor rendering work or assessment of the light.
I love older lenses for their aberrations and peculiarities that produce pleasing results I find difficult to obtain in rendering. Aesthetically pleasing imperfections, if you will. They're just as likely to cause flat appearance with poor lighting or bad rendering as the modern lenses. The aberrations and flaws often mask it, but it's really no different. They can't achieve in a technical sense what the modern lenses can, no matter what I do, but they can make very pleasing photographs nonetheless.
G