The sound has been great so far! I'm only using a 5.1 setup, so not taking full advantage of what this can offer. However, I really chose this model for the HDMI 2.1 compatibility, especially for Variable Refresh Rate (VRR). Using my XBox One S, I have had a lot of video dropout (goes black).
It's probably a HDMI cable quality issue, but I haven't been able to find the secret button push needed to get to the HDMI diagnostics function that is supposedly in there somewhere. So for now I'm using the HDMI ARC audio from the TV back to the receiver to work around the video dropout.