All of this discussion seems to ignore some of the handling and design of these cameras. As far as handling goes, the Alexa and the C300 are great. Easy peasy to figure out immediately, and the results are predictable. The GH2 is a huge pain in the ass to shoot with. It's got a terrible menu, tiny tiny buttons, a crappy mount, brutal rolling shutter, crappy dynamic range and has to be hacked. I love it still, don't get me wrong. But everyone I know that uses one, instantly loves the Alexa. And I really like the Epic with it's onboard 5k, and versatility. I picked up a C300 and was shooting confidently immediately. I guess I'm trying to say that there's more to these cameras than a single setup scene contest. Camera design, menu layout, and usability weigh heavily when camera choices are made. For me, the best camera is the one where you're not thinking about or dealing with the limitations of the camera, but you're getting on with the business of shooting. I've shot a ton with the GH2, and it's shortcomings are always an issue. For what it is, it's fantastic, but it is not a joy to shoot with like some of the other cameras that were tested here.
That would be an interesting camera test. Same scenes, same crew - but just document what they have to do different to get the same result.