I find them valuable. Not to same degree as the ground-up art demos, because the construction stage interests me most. But correcting flaws raises unique problems that you might not encounter otherwise.
For me, increased video-speed actually aids comprehension - I tested, & 3x seemed around optimal for me. Any slower & my mind wanders. Although real-time speed is interesting on a personal level, mostly as a yardstick for my own workflow.
If anything, I'd increase emphasis on text explanation. It's the give-man-a-fish/teach-man-to-fish dilemma.
Oh, & more prog. That's vital.