Not sure yet... I definitely like the files better after ISO 1600, but I'm wondering if the shots below that are softer than I was getting on my 5DII. Just made a post about that actually, to see if anyone else has any experience with it.
So I did some studio shots, and looks like the 5DIII is as sharp if not sharper than my 5DII. Also, focus was pretty much nailed on nose of teddy bear test subject, while 5DII was kind of all over the place. So looking good.
One thing to note, I had to bring down the exposure on the 5DIII shots by .25 in Lightroom, so that camera is over-exposing ( or more sensitive to light ) than the 5DII. I used the same lighting of course, and all 3 shots with the 5DIII were over-exposed as compared to the 5DII, so it's not light variance. The strobe is an Einstien BTW.