Sooooooo good!
Been shooting weddings (photos and videos) and it performs sooo well!
Photos:
Autofocus is great, locks on to human and animals eyes as it should. Not perfect but it's very very good. I highly recommend this for weddings photographers especially when you're someone who shoots nearly 4000 photos per wedding, the files sizes are like almost 30mb which is better than having to deal with 90mb files sizes from the D850 when shooting weddings! I've paired this with my f-mount lenses mostly with the classic 24-70mm f2.8G and it does an amazing job, you don't need the Z mount version unless you're heavy on the video aspect.
Videos:
Amazing. that's all I can say. I've been shooting on H.265 10-bit with N-Log and thanks to the RED luts that we have for free, color grading has become an easy work, and with the 5.4K 60p, it's *chef's kiss*