I use this every day. Being able to quickly jump forward/backward 10 seconds is also very useful. I recommend setting keyboard shortcuts that agree with equivalent functionality on your desktop player like VLC.
There are also some chrome extensions that allow you to speed up any html5 video (so it works on youtube, Vimeo, and even Netflix!) highly recommended.
[1] https://chrome.google.com/webstore/detail/video-speed-contro...