[davidmanze]

That's like 500 horsepower in a truck vs a Ferrari.

I was having "an enormous problem" understanding the optical properties of this lens with regard to quality of it's out of focus rendering, consulting such publications as "Leica's approach to quality bokeh" and "Problematical image rendering with advanced large aperture lens design" .

   

     Then after your reference I found the answer in " Monster Truck Monthly "!

[Klaus]

Well, it's about the raw power of the large aperture vs the refinement of this output. 

Thus I reckon that Truck vs Ferrari feels alright.  B)

[davidmanze]

  Got it!  The updated AF version will have a V8 HSM, got to be a turbo right, you know for sports photographers!