I wanted this lens so bad ten years ago. It was quite pricey than but the price is three to four times today than what it was back than. Now I often see it listed for 1000 Euro or even more. Therefore I see no great use in buying it today apart from being a eastern bloc lenses buff or collector. The bokeh is quite swirly. I don´t know about sharpness but doubt that it will be impressive unless stopped down. If you want awesome bokeh, better buy a Canon 85/1,2 or some fast Leica glass for that money. If you should want it nonetheless, I think the M42 version is both cheapest and easiest to adapt to modern DSLRs. There is also an Exakta version and a Contax version (the latter the most rarest I think).