Panasonic has led in Contrast based Auto Focus when it comes to speed and low light acquisition, however some are still not happy with their tracking Auto Focus in video mode. In mirrorless systems Fuji and Sony have featured Phase Detect on most of their bodies with Olympus on their E-M1 M1 and M2.
Canon on the other hand have developed their own system that features Dual Pixel AF for tracking. There is some debate as to which is better. Panasonic having a large share in the Indi video market would certainly make many happy if they introduced Dual Pixel AF tracking Auto Focus system in their future GH5 and GH5s as well as their other model updates. With increased processing power Panasonic has improved their DFD - Depth From Defocus tracking AF system. DFD uses lens out of focus information to determine distance - so of course Panasonic has to analyses each lens - The Contrast based AF system over-shoots the distance and then comes back - this over-distance action is now a lot less noticeable in the G9. Most will agree that although the new DFD system like that in the G9 is omproved - But the Pahase and Dual Pixel system are more confident for tracking in video continues Auto Focus.
Once Panasonic implements Dual Pixel on their next sensors they will have extremely capable hybrid cameras.