Just my 2 cents- do not have an A7S although I am intrigued and would certainly like to try it- using 1Dc now since it came out, and had shot with a Scarlet a few times. the 1Dc is just it's own animal. I knew nothing- zilch- about making moving pictures (pretty obvious if you look at my technical issues). I needed a camera that worked with existing glass, could also shoot fashion/ sports/ studio / tolerate weather and used my CF cards. I cringed at the price but had a lot of Canon glass already. And I must say: arriving a 10 pm with one or two street lamps, no crew, an actor, a rough concept, and 1 hour: being able to shoot 28000 ISO for B&W (lower for clean color . . .) simply pulling focus before the take (and once in a blue moon pulling during- what am I thinking . . . ha)- shooting 4K handheld and stabilizing in post to scale to 1080 . . . I have been able to come up with cool footage for a beginner. I watch what Andrew says and I read every review - and then used some equipment, and came to the conclusion that that the 1Dc was "right" for me for a lot of reasons. But there is simple one thing that is tough to explain where I think the 1Dc may excel compared to the other sub $8k cameras now in 4K (although I am going by Scarlet, prior 5D MkIII and online vimeo's of the newer smaller): The Picture. Filmic compared to others. The digital grain on the sensor looks almost organic. Not exactly like film- but it's own sort of specialness. And when it comes to cameras, I care about picture more than anything else. More than anything. (Even money - when I can stretch for it.) The 1Dc is spot on now for the animal it is - in its pricing - for those who already have invested in Canon glass. Am I sorry I bought it when it came out? Not one bit. Will be using this beast a long, long time . . . (www.gerstvisuals.com for some moving footage)