The issue is that every image taken with the camera, no matter what ISO, F stop, RAW, JPEG, etc. is coming out very milky/blotchy, almost like the camera is applying heavy NR to every image.
Sorry about your luck but thanks for bringing this to our attention. When mine arrives, I will test thoroughly. The 5DM2 I just sold would easily outperform what you sent.
I wonder how critical anti-alias filter alignment is? If it were askew relative to the sensor, I speculate it would create some strange NR looking results...