I received the camera, read the manual (which all the "influencers" with their videos at product introduction did not have (as it only became available today worldwide), and shot some video.
Here is what I learned, the good:
1. Audio: Manual audio, with fine settings, plus options for a limiter and/or wind reduction. Audio meters; mic-in jack but yes, no headphone jack but meters do not lie.
2. 4K video: You can shoot 4K video with all manual settings, or with ISO auto, adjusting separately shutter and aperture and ev.
3. You can view a histogram in real time, but no zebras.
4. In auto ISO you can half press the shutter to get a readout of what the ISO actually is in real time. No other camera allows this (well, not any Panasonic or Sony camera, even mirrorless).
Output: In 'Standard' picture style the colors are nice, highlights are a little hot, but easy to tame in post.
5. The 4K bitrate is actually 123 Mbps, not the 100 Mbps in the specs - that is good.
6. Focus: You have the choice of servo (active) focus and there is an icon on the screen to turn it on and off. This is what I do - I select with my finger what I want to be in focus on the lcd, that puts the focus in tracking mode, so that if the subject moves focus follows. If the subject is static, sometimes a change in light causes the focus to shift, so for static subjects I turn off servo and the focus is then locked in place. So, focus is fine. You will see in the video how it does, with most shots using the servo (tracking) focus because the flowers were moving around in the wind.
7. There are three stabilizing modes: optical only, and two digital supplements ,which crop. My video only uses optical stabilization to maximize resolution. There is also a special stabilization for panning (why? so the stabilizer does not resist purposive movement up and down or left and right for pans)!
8. Built-in 3-stop ND filter - what a convenience!
Ok, here is a 30p 4K video I shot today in 'Standard' Picture style, with sharpness turned down one notch.
Oh, yes, the bad: Camera (and I) overheated after 45 minutes of shooting short clips. Worst-case scenario: 90 F in direct hot sun.
7. You can shoot 30p RAW video in 5.7K. Yes, real RAW video. For over 2 seconds at a time in RAW burst mode.
This 4K video was shot RAW 30p: