DxOMark published their test results for the Sony RX1 camera (see my first impressions) and they are pretty good - the RX1 scored #4 on their overall rating list right after the Nikon D800E, D800 and D600:
"Ranking 4th overall in the DxOMark Sensor Score Ratings the Sony RX1 compact camera performs as well as and better than many professional DSLRs. Featuring the same full frame Sony CMOS sensor used in the Nikon D600 we already knew how impressive the results could be and engineering it into a compact shell with a fixed lens hasn’t negatively affected picture quality. ISO performance isn’t quite as good, but nearly, and Sony should be congratulated for pushing the boundaries of camera technology with the RX1."