In my past experience, the cost of Leica SL lenses has been justified by their quality and ability to facilitate the highest IQ. And it was with that in mind that I'd ordered an SL Summilux 50mm F/1.4 for my S1r. But a little voice had suggested, given the huge price differential, that I obtain a copy of the Panasonic Lumix S 50mm F/1.4 to compare. That said, I'd just repacked and dropped off the Summilux at the UPS for return. The roughly $3,000 difference in cost, in my mind and with my eyes, could not be justified. In fact, I could not really see a difference with everyday subjects, and found the presence of the Lumix aperture ring to be beneficial and pleasant. The SL was of course somewhat lighter, but if I'd kept it I would have been $3,000 lighter. The Lumix is great. It's silent, lightening fast AF and beautiful rendering. None of what I've said was meant to belittle the Summilux, but was intended to show that Leica, IMO, may no longer rule the day.