After many years using Panasonic Micro Four Thirds cameras, I, like a lot of people who do both photography and video, am switching to the Sony A7 iii. Why?
Basically, because Sony cameras have been improving by leaps and bounds over the past few years, to the point where there are only a few ways that the Panasonic cameras are better, and many ways that the new Sony A7 iii is better.
It used to be that the Panasonics were better than large-sensor cameras in almost all ways for video. Sharper, longer battery life, much easier to use, better stabilization, cheaper, etc. The biggest problem was slow autofocus in video mode, but the large-sensor cameras were considerably worse in this regard. Two other important disadvantages of the Panasonics were that because of their relatively small sensor size they were not as good in low light, and weren't able to produce that creamy shallow depth of field look that a bigger sensor allows, which looks so nice for events such as weddings. However, there were adapters I used that partially eased these problems.
However, for photography, that lack of super shallow depth of field was more of an issue; it really makes a big difference for portraiture. The low light deficiencies also meant I more often had to use the harsh light of a flash unit. So I wished that a true hybrid camera would come out, excellent for both video and photography, which didn't cost an arm and a leg.
And now, such a camera has arrived! Unlike large-sensor cameras of the past, the Sony A7 iii produces super sharp 4K video, has long battery life, and has superb video autofocus. Ease of use and stabilization are still not as good as the Panasonic but much better than before, the low light performance is even more outstanding than before, and, it is affordable!
So get ready for some big improvements, especially in portraiture, in low light such as at wedding receptions, and in video scenes where people are moving a lot and focus is critical. Be on the lookout for samples once the camera arrives.