I know there are two versions of the Summilux. The first is the ASPHERICAL version and legend has it this item had hand ground aspherical elements that proved too costly for series production (I once heard that the only person who could grind the elements died and no one else knew how to do it properly... this sounds like a Leica myth to me, but maybe someone knows for sure). The much more common ASPH version has molded aspherics and is the current model. As to imaging differences between the two, the ASPHERICAL version is quite rare so only a select few would know for sure.