I love to load videos up from the web inside QuickTime Player so that I have more control over their playback speed.
If you haven't already, learn how to open up a video from the web in QuickTime Player.
You can speed up a playing video up by Option+Clicking repeatedly on the Fast Forward button. It will increment 0.1x with each click.
Now you can enjoy watching tutorial videos at 2x the speed and save bundles of time.
You can go as fast as you'd like. I notice that certain voices are better than others for going really fast. Every video you watch you'll probably use a different speed to get right on the cusp of as fast as you can while still hearing the words.