I loved my Canon gear and used it for 20 years. The image quality the Canon gear produces is outstanding and the colors are wonderful. But there were many times the autofocus system missed, especially when tracking a bird in flight. This was especially true when the bird was flying in front of a cluttered background. Even when I think I did everything right and had the autofocus sensor actively on the bird, some frames were sharp and in focus and others were not. Some were close and others were a total miss. Many times the best frame in the series was one that was not accurately focused, which was very frustrating. Since trying out the Nikon gear, it was evident the autofocus system is different. And better. Using the Group AF, I can now place the active sensors on the bird and almost every frame, if not all of them, are focused accurately. It even somehow knows to keep focus on the eyes of the bird, not just a random part of the wing. It is uncanny how well it works and makes shooting birds in flight so much more rewarding and fun. I do still find myself slightly preferring the Canon image quality, but with so many more keepers and increasing the chances of capturing that perfect pose, Nikon wins for me.
This animated GIF tells the story the best. This is every frame in a series of the sandhill crane coming in for a landing. The light was still quite low before sunrise and I was shooting at ISO 6400 with the Nikon 600mm f4 on the Nikon D5. Every frame is perfectly focused on the eyes!
Can your gear do that?