One: Sports and Nature Photography
The 1DX MKII is Canons current flagship photography camera and an extremely popular camera with wildlife and sports photographers. The camera can shoot 14 fps stills with continuous autofocus tracking, which makes using it in fast-paced situations, really easy, and photographers can rely upon this camera to do the job in demanding scenarios.
Two: Build Quality
The 1D line from Canon is well known for its solid build quality. Its built like a tank has some brilliant weather sealing and can handle the most demanding situations. Everything about this camera screams of a professional build quality, its solid, big and robust.
Three: 4K 50/60p
On the video side, 4K 50/60p is a big deal. In Canons lineup, the only other two cameras to have 4K 50/60p are the C200 and the C700. It's brilliant to have those frame rates for half speed slow motion, and in 1080p, you can even go all the way up to 120fps, which is brilliant. The files are really high quality too, the only drawback is that the files are motion JPEG files, which are very processor intensive, so most people will transcode the files to something like ProRes for editing.
The 1DX MKII isn't the smallest when it comes to photography cameras, but when it comes to video cameras, its actually a really nice size. It's big enough to impress clients, but not too big that it becomes an issue to travel with.
Five: AF Performance
Now it wouldn't be a Canon video without talking about dual-pixel autofocus. The 1DX MKII has the same dual-pixel autofocus as Canons cinema cameras and is really, really reliable. Just like on the C200 and EOS R, you can control the AF through the touchscreen, which is a really easy way to control the AF quickly.