Those are terrific photos, simply great. And, I'm sure that the photographer contributed far more to these pictures than did the camera.
I have a Mark iii. I've said often that it doesn't make me a good photographer but it gives me the opportunity to be one. For me it's a case of total love. What I love most about the camera are its ability to suppress noise even at relatively high ISOs, its terrific dynamic range and, above all, its superb and very fast autofocus. I do mostly wildlife photography in the field and sometimes in zoos. I have the camera's autofocus more or less permanently set as a single point, centered, and in A1 Servo mode. That works brilliantly for me. Prior to getting this camera I'd never been able to capture birds on the wing. My other camera, a 7D, is outstanding but its autofocus just doesn't acquire objects quickly enough for my taste. But, the Mark iii is lightning fast and I've had lots of success with it. Most of the time I team mine up with the 100-400 F4-5.6 L IS. It's a winning combination for me.
So, if you can afford it buy it. You will not have buyer's remorse.