4K is detrimental to the quality compared to 1080? Please. I agree 100% with your assertion that pixel count isn't everything. I use the BMPC which is 1080p and I love it for narrative work because of its raw and pro res options and great dynamic range and color rendition. I also have a hacked GH2 with Moon T7 and for sure it gives a pleasing image, but better than the GH4 in 4K? I mean, you can have your own opinion, and I know there's a very few that share your belief, but I, as well as I'd surmise a vast majority would take the GH4 image without thinking twice. Saying 4K is detrimental to the image? That's pure hogwash.
Very impressive. The image is absolutely stunning. In my mind, and to my eye based on these limited tests, this is the camera to take the step into film's domain, and I don't say that lightly at all.
Gh4 does 200mbs in 1080p, my guess would be at least that nitrate for 4K 10 bit 4:2:2.