I loved his rant about space heaters. He showed a bunch of different products, all the same kind of heater, down to having identical 1500W output - but they were rated for small, medium, and large rooms, with proportional pricing. He went on to explain some basic thermodynamics (as opposed to marketing)...
The one on traffic lights is way more interesting than it sounds! Everybody should check it out. There's also a really interesting point he makes at the end that applies to something a lot of people on HN might relate with https://www.youtube.com/watch?v=GiYO1TObNz8
The toaster one is alright, it kinda bothered me when he said there was "literally NO reason" to design something the way it was (I think it had to do with the position of the coils) - obviously there is, it's probably just not a reason he'd like (cost, ease of manufacturing, etc). It makes me wonder if there was other info he skipped on because it "wasn't important" or "stupid". That's a pretty minor point though, overall his videos are very good.
Agreed. This is something my 12 year old son really enjoys watching as well. I like that he usually does a pretty good job of striking a balance between deep dive and conceptual high points. On school nights, he will sing "Technology connections" to the melody of Lucky Charms "Its magically delicious". Try to not do that the next time you see that channel...