Micro Four Thirds occupies a strange part of the photographic world. You’ve got people who’ll never consider it purely because of the size of the sensor, regardless of what it might be able to do, and then you’ve got the other extreme that is ridiculously loyal to the format, regardless of whether they’re shooting Panasonic or Olympus.
Both cameras offer some distinct advantages over the other depending on your needs. The Olympus E-M1 Mark III, released in February 2020, has probably the best image stabilisation system out there of just about any camera, offering up to a whopping 7.5 stops of stabilisation with some unique functionality like Live ND and Live Composite features.
The Panasonic G9, on the other hand, is quite a bit older now. I first got my hands on a pre-production model in December 2017 and the camera was released to the public in January 2018. So, the Olympus has the age advantage. But thanks to a firmware update released last November, the Panasonic G9 is now almost as much a video powerhouse as the GH5.
Thankfully, no matter which brand you go with, you can use the same lenses with both. So, there’s nothing to stop you from buying into both systems if you want cameras tailored to both stills and video.
For me, I’ve only really gotten into Micro Four Thirds recently. I’ve had the YI M1 for a few years, but it’s mostly just sat on the shelf as it took a year for the firmware to be released that gave it its most useful functionality. But recently (within the last month) I picked up a few Panasonics just for shooting video. And so far, especially for what they cost, I’ve been very impressed.