After only a couple of days with this lens, my worst fears have come true. It is absolutely as brilliant as everyone else has written about. After I ship it back to Lensrentals later this week, I will promptly place my order from B&H for a brand new copy. Simply stunning with nothing bad to say at all. I do look forward to the release of the SL2, but in the meantime, the Panasonic S1R provides the resolution necessary to show off what this lens is capable of capturing.