I saw that video a while ago, and it was quite painful to watch. As are all of his videos. It was all time that I can never get back, but I know better now. He doesn't seem to know what he's talking about, misses the mark often, and is only internet famous due to his friend Beato.
Some of the stuff he left out in both the Hiwatt and Orange videos is that all the prog bands were using them because they were loud high fidelity amplifiers. Comparing a modern Orange or Hiwatt or an original is comparing apples and pumpkins. Bands like Wishbone Ash, ELP, King Crimson, Moody Blues, Genesis, Curved Air, and many other bands used them because they were loud, and very clean. Yeah, you could eventually get the speakers to break up and give you distortion. But you were in pretty loud territory at that point.
Whatever. What do I know? I only own some of the real stuff.