The Video Speed Controller browser plugin changed my life. With the key bindings you can dynamically adjust the speed to the complexity of the content and always be watching at exactly the rate you can process it.
[ speeddown
] speedup
v display speed settings
Speeds of 4x has audio cutoff, 16x is max playback speed
Also, enable captions on video helps out a lot when speeding through a video, in the event you misheard something at faster playbacks