I had been considering selling my 1ds mk111, and getting a 2nd 5d mk11 and banking the leftover money. Then I got a job for an article of bike riding. I used my 1dmk111 for most of my shooting but when I wanted to use my 16-35 so I wanted to use my full frame bodies for wide angle shots. I found the 5d mk11 simply did not cut it for fast action not just the slower frame rate but the responsiveness of the camera as well. the shutter delay is greater. So I found their is a reason to keep both bodies and not just get 2 5d mk11's. I do like the 5d mk 11 for street shooting and landscape, for fast action it simply is not a camera for that use.