Can an actual sensor engineer shed light on this matter? It's totally useless comparing a dedicated RED video sensor to a dedicated stills photo sensor, the R&D process is completely different. So what if the RED 4K sensor can capture 18 stops of DR? It's only 8 megapixels (4096x2160) for God's sake, I bet it will absolutely SUCK at taking stills photos.
A couple of years ago I was shooting 8 megapixels on my 20D and doing just fine. Heck, I'm normally on mRAW on my 50D getting 7 megapixels. Go check out some of the photos taken by professional photographers on the Red Epic/Scarlet and see what you think