I agree that most of the slides would require further explanation but I still found a bunch of commands I've never heard of and actually could make use of, eg git bundle and git rerere.
Although not totally worthless, it is nearly so. It is ~350 slides, most with a single word. To find those commands you've never heard of, you have to wade through a deluge of meaningless, when out-of-context, crap. Most readers, like me, probably said "not worth the time" after about 20 slides.