I’m not going to go into a technical breakdown of the Canon 5D mark iv's capabilities (there are already plenty of those out there), but I will touch briefly on what I have learned through trial and error. I have read quite a few mixed reviews about the and filming. Some are good, many are bad. I’ve been filming with it for quite a while now, and it definitely has its strengths and weaknesses.
First off, the picture quality is fantastic if you can get a handle on the focus system. The autofocus is amazing if you can find the correct settings for your situation. It took me a while to figure out how to film with it, and in combination with my Zhiyun Crane 2 stabilizer I have gotten some fantastic footage.
It is not good, however, with moving shots of any significant speed. That is where it really breaks down in my opinion. Even with the frame rate turned up and the shutter speed as high as possible, there is still distortion in the image when the camera moves. On a tripod or slow-moving stabilized shots, it works quite well, but it is not a run-and-gun platform.
I am Adobe Certified, but primarily edit in Davinci Resolve. Color-correction is great in Davinci, less so in Premiere but not horrible.
Overall, if you are doing more static shots it is a fantastic camera. For moving shots or more dynamic shots I would recommend looking elsewhere. If you want a camera that takes both fantastic pictures and great video in controlled situations, I highly recommend it. If you primarily film action and fast-paced reactive shots it is not for you.