Damn! Even my Zappiti One 4K HDR player plays the UHD 2160p 4K77 in a jerky way. I’d never have thought that could happen since it allows very high bitrate. The audio plays smoothly, but the video, damn! I’ll have to stick to the 1080p for now. My TV is 1080p for now anyway. I also noticed that the blacks were not as black on the 2160p, but it’s probably the 10-bit stuff on my full HD TV only that causes that. The 1080p looks quite terrific. Thanks guys!