I think a good full frame 4k image for under $5000 is pretty reasonable ($2500 a7S + $2000 Atomos Shogun + SSD's). GH4 looks like it will still be the go-to indie filmmaker camera for awhile because of it's internal 4k 24/25/30p and (somewhat soft)1080p96fps at $1700. Fast SD cards + optional $400-480 Metabones Speed Booster make it around $2300, or less half the price of a7S 4k kit, for a 4k image around super35mm field of view but not as good ISO. I'm looking forward to seeing more 4k a7S footage (rolling shutter worries me) as well as what raw can bring to the BMPC 4k camera (if only they offered a sony e-mount version to allow for a speed booster!). The a7S and BMPC will obviously each have their strengths, but the GH4 seems it will be the winner when it comes to portability, file size to quality ratio, and price.