I have definitely been told by people that sharing this with them has significantly improved their quality of life, so I share it any chance I get. It's especially handy that it works with almost all online videos. (I have no affiliation, just a huge fan)
In fact, writing this comment inspired me to submit it as it's own top level post on HN.
That being said, Youtube itself is pretty good at this, with the shift+> hotkey, and the recent addition of 1.75 which is the sweet spot for me.
EDIT: What I fantastic extension, has all the options I could want (exclusion list, custom hotkeys, hide by default, etc).