I have upgraded my 55xd9305 yesterday and it proved to be a bad move. Since then a lot of judder specially on 4K stuff from Amazon and YouTube. It settles if left alone for couple of minutes. Clicking a buttong on remote such as volume or action will again introduce judder. I also noticed that while watching some 4K HDR on Amazon last night, the sound was out of sync with video as well. I hope a fix comes soon.