Some first impressions:
-AF is
very fast and accurate
-Ergos are cramped - this camera is begging for Gariz stick-on soft release to make easier to trigger shutter release with inside of first knuckle
-My camera has no significant decentering, but edge performance at f/1.8 is pretty bad. Gets better with stopping down of course.
-Sensor is spectacular. Low ISO dynamic range is great, and high ISO detail/noise is equally great.
-Controls are adequate but I'd like a couple more dials.
Overall I'm very happy with the purchase. Makes a very easy camera to grab and go when a bag is not desirable.
One from the first "roll" (25mm f/4 ISO 1000):
DSC00020 by
Amin Sabet, on Flickr