Above you can see a mini-doc shot on the GH5s by Cinema5D.

Preorders:
GH5s at BHphoto, Adorama, Amazon, FocusCamera and Panasonic.

Dpreview posted their full G9 review:

Ultimately, we gave the EM-1 II a gold award, but the G9 walks home with a silver. Here’s why: though the two are equally competitive, the Panasonic is playing catch-up to a camera released more than a year ago. And just being competitive is not enough to earn our top mark. But it is still certainly worth your consideration.

Panasonic Preorder links:
Panasonic G9 at BHphoto. Amazon. Adorama. FocusCamera. AmazonDE. Wex UK.
GH5s at BHphoto, Adorama, Amazon, FocusCamera and Panasonic.
Leica 200mm lens at BHphoto. Amazon. Adorama. FocusCamera. Amazon DE. Amazon UK. Amazon IT.

Join our Panasonic G9 Facebook group.

Cinema5D posted this:

The image on the GH5S is cleaner than the GH5 across the board. There is really not much more to say other than it’s by far the cleanest and most sensitive Micro Four Thirds camera that I have ever seen. It will be very interesting to put it up against the Sony a7S II.
Mind you that the GH5 can only do 12,800 ISO max – while the GH5S can go all the way up to ISO 204,800. However, it can “only” go up to ISO 25,600 when in V-Log mode.

And Kai tries to answer the simply question if the GH5s is or is not worth the upgrade:

GH5S – Shooting Slow Motion / Variable Frame Rate video (PhotoByRichard).
GH5S – First Impressions Review (Mirrorlessons).
GH5s Preview | Features & Impressions by Dan Watson.
Panasonic Lumix GH5s – First Impressions Review (Mirrorlessons).

Preorders:
GH5s at BHphoto, Adorama, Amazon, FocusCamera and Panasonic.

Preorders:
GH5s at BHphoto, Adorama, Amazon, FocusCamera and Panasonic.

Gorond Laing made a perfect job explaining the advantages of the multiaspect sensor. So please click over to CameraLabs to see this! And this is Gordon’s GH5s video:

Preorders:
GH5s at BHphoto, Adorama, Amazon, FocusCamera and Panasonic.

Imaging Resource compared the new GH5s vs the A7sII:

“At both 12,800 and 25,600, the GH5S looks slightly better than the A7S II at the same ISOs, which is both unexpected and subjectively highly impressive for a camera featuring a sensor that is a fraction the size of the other.
A sensor significantly smaller than the full-frame A7S II is beating that camera in low-light performance. I never thought I would see the day. With these test results, it’s hard to argue that the GH5S is not the new king of low light.”

Some more Panasonic GH5s vs Sony A7sII tests: