Very impressed with the speed of the focussing and the image quality even at high ISO. I used it at Chester zoo the other day on Shutter priority with auto ISO. I wanted to try it out and I am very impressed. Next testing is Manual and auto ISO. But the speed of focussing even with my 100-400mm lens was what really impressed.
I have just updated my Canon 5D Mk II to a 5D Mk IV. I am still learning all the new options especially the Auto Focus. My first impressions are that it will be a real time saver when it comes to photographing anything that is in motion, especially wildlife.
I have already customised it three times, but I think I have it fine tuned for me.
The really impressive difference for me is that I can auto focus with my 100 to 400mm Mk 1 plus x1.4 extender and it tracks quickly.
I have been spending some time recently refreshing and practicing my Restoration and retouching skills using a workflow that starts and finishes >in Adobe Lightroom with a visit to photoshop in the middle. check out www.stevepeacock-photography.com/ to see samples of my work.