I just shot my first wedding with the a9 this past Saturday. I love this camera so much! The AF system is a beast! I did notice some severe banding during the reception. It only affected 10 images in the same scenario, but I shot just over 2,600 throughout the day, so that's like 0.4% =P
Crazy mixed led lighting (tungsten and incandescent equivalent spot lights all throughout the room). This was during a prayer before dinner was to be served.
Pictures are SOOC, just exported as jpegs. Electronic shutter, obviously no flash was used. No banding in the 3rd image? Hmm...?