And for the most part, I will have to say it's passed with flying colors.
It isn't made for sports or fast action photography, or wildlife photography, but you know something? I was able to track and photograph birds flying overhead, with amazing accuracy. With the high speed continuous shutter not being as loud as its' predecessor, it can be used for wildlife photography without scaring away your subjects, most of the time (there are always some that are camera shy).
Over the weekend, I used the 5D4 at the Perth Zoo (not many moving subjects) and at Herdsman Lake, in Selby, where there were a lot of moving subjects.
Perth Zoo:
Silver Gull doing a flyby - The AF tracking kept the gull in focus
AF focusing, AI Servo mode, kept the dragonfly, in flight, in focus.
Auto ISO works a treat, and the new sensor; even in shady conditions, you don't get excessive noise.
Details, sharpness and better dynamic resolution.
Herdsman Lake:
AI Servo Auto Focus Tracking keeps the running Purple Swamphen in focus.
Tracking a Kite overhead, the 5D4 kept the subject in focus.
Nankeen Night Heron coming in for a landing.
Straight from camera, the dynamic range is heads and shoulder above the 5D4's previous incarnations.
To sum up: it's not just a few extra tweaks or a new coat of paint. Many of the above shots I would not have been able to do with the 5D3. Not saying the 5D3 is a bad camera, but it's successor is just that much better.