From Slashcam: https://www.slashcam.de/artikel/News/Panasonic-GH5s---Die-Unterschiede-zur-GH5-am-Vorserienmodell-naeher-betrachtet--Bildqualitaet---Tendenzen-des-Vo.html
"Although the sensor only offers a 1: 1 readout due to the size of the sensor, the first impressions of the debayering look very cinematic: the finest details are clearly filtered, which accommodates the typical cine look and covers most debayering problems in a 1: 1 readout. So no chroma streaks and no zipper artifacts like many competitors. The clean 4K sharpness of the GH5, of course, can not be achieved due to oversampling due to additional pixels"
GH5 seems cleaner in low iso.