Make no mistake about it, this is a top quality receiver. The 4K aspect is a pass-through.
However, that can be important if you are interested in using the receiver for all your 4k input devices. The 801 has at least 4 HDCP 2.2 HDMI ports.
As far a picture quality goes, I recommend (highly) that you consider a professional calibration. I have the 78 in curved Samsung and it made a unbelievable improvement to the image quality that I was seeing. If you are a video enthusiast the money will be a minor issue compared to the benefit you will see. The receiver is first rate. My recommendation (if you buy it) would be to run the room calibration. Once you've become accustomed to the sound, then I recommend that you modify the multi-channel sound to your preference. The software will make switching back and forth (for comparison) easy. Another suggestion I'd offer is to be patient with yourself and the set-up process. I've had my set-up for a while and am just now getting things the way I like them. Overall very satisfied at this point. Regards....