I was just reading a blog post on thelensrentals.com blog, and Roger said the following: "We then used Adobe’s DNG converter which handled the files with no problems and didn’t manipulate them at all, so we used raw to DNG conversions for all the cameras to make sure things were equal."
Which I find a smidge odd, sine he was testing a 5D MK III and as far as I know the Adobe DNG converter hasn't been updated yet, but... perhaps it is worth trying?
Neil