[photonius]

It's a lens with some unique features not found on modern lenses (it's even considered a flaw)
If you are interested in such features why not ?
if you like swirly bokeh or soap bubble bokeh either you look for old vintage lenses with those characteristics  or you buy some exotic lenses like this one, they are special lenses with special effects not lenses designed to give optimal image quality and smooth bokeh

I think you are talking about the Petzval 55mm lens.  

But the Petzlav 55mm lens that Klaus posted, is a much rarer beast...