For the most part it is great to hide latest horrible Youtube redesign and to bring back functions like frictionless plalist/watch it later use without having to go back and reload the page. But it feels it does something to the video itself and while watching i can feel video looks different than when add-on is not enabled. And it also messes up home page layout and there is no setting to fix it (i see only 2 videos in a row instead of 3 with my size of browser window).