My experience is ZERO. I had to read the notes at GitHub to realize this is NOT an actual working browser extension, it is an EXPERIMENT, and the notes specifically state "If you opted in to participating in Mozilla’s research you may have been assigned to a control group for which the button is not available. In this case, in order to support our research, we ask that you leave the extension installed for at least one month and continue to use YouTube as normal." WHAT IS THE POINT of having a control group that cannot access the extension's function? If I can't actually use the extension, why have it installed?!?!?