I was able to grab a few frames from this amazing lens today before my back locked up.
ISO50 @1/110 SS @ F5.6. Wanted to go to F11 but did not have my tripod. I did experience some technical issues with firmware getting along with body/back firmware but was able to get a few sunrise shots on Sunday. The lens is everything they say it is. I experienced no vignetting and no distortion and it's sharp edge to edge and color and contrast seems spot on. What more could a guy want? Sharpest piece of glass I've laid my hands on in some time. I believe I'll take advantage of P1 $2k discount on this lens with the purchase of an XF .