I am seeing an increase in the effective overall bitrate of 4k footage (mp4 and mov, using MediaInfo). With 1.0-1.2 it was rarely over 80-82Mbps, now I am getting up to 96Mbps (@25fps). This might imply an even better image quality.

This is the second firmware update, right? Didn't we get the GH2 hack after the it's first firmware update? Just sayin'...

Looking at these actually it isn't using the entire usable frame of the GH4, so its a crop but each aspect could have a use as a video format. Certainly using anamorphic lenses could be helped out by shooting the 4:3.

looking at the spec its somewhat disappointing that the 4:3 3:2 and 1.1 modes seems to be further crops from the 4k frame. Meaning wide shots in this format aren't going to work very well!

[4:3] (Size: 3328k2496) [3:2] (Size: 3504k2336) [16:9] (Size: 3840k2160) [1:1] (Size: 2880k2880)

Will do some tests once this has installed (not reading it at the moment).

Downloading now. Lets see how this 4K photo mode works!