I just picked one up a couple days ago as well. I am liking it so far. I bought it as a backup/2nd body for my 5D3 and upgrade from my 60D. I am loving the new af for both video and stills, since I will be using this for wildlife and sports and most likely bts videos for my big shoots. I shot this video this weekend to test out how the AF would do under real life situations, so I let my son loose in the forest and tried to keep up with him. I was impressed with the overall quality and the ability of the camera to track him and stay in focus most of the time. I also like the little things like the video switch! I haven't done any real stills tests yet, but am going on a birding hike shortly and will post pics when I get them. I will also be doing a lot more filming with this in the near future and will post as that comes up as well. Here's the video link:
How is the sharpness and aliasing and low light? Relative to the Mark III (which I consider very soft with no significant aliasing and excellent low light).