An unscientific test... ignore any posterization due to 8 bit jpeg processing.
Took this @ ISO 100:
Moved some sliders in Lightroom 4 and got this (8 bit jpeg posterizes slightly):
I continue to be amazed by this sensor in my initial 24 hours with it... VERY similar in response to the Aptus II 6 I owned, but with less (NO!) noise in the shadows at ISO 100.