Agreed - they are really good videos; I got about half-way through the course some months ago and plan to return to it when I return to Hebrew. Hopefully they'll have doubled the course length by then, too. Certainly they are the best online TPRS-type lesson I personally have ever seen in any language.
Of course, they are teachers with considerable experience teaching in this way, with a lot of other language teaching experience, and some study of language acquisition. Everything is done very thoughtfully and carefully. And I think (?) they are devoting most of their time to it. A lot of the imitators are people with no direct experience of teaching in this way, who are doing it on the side - it's not going to work as well.
My one issue was the expectation to watch and re-watch and re-watch the videos, which is kind of necessary with this method. Fortunately if you have a bit of other learning under your belt, you can skip some of that. But without it, it would get repetitive. They have worked at reducing this with the review lessons. But it still feels to me like this kind of learning would work far better as part of an integrated system of learning - with reading, flashcards, etc - so that you weren't relying on re-watching a whole video because of a word you had forgotten, and so you could reinforce things in a different context. To the credit of these two, they are slowly producing written summaries that let you do this for yourself, quizzes, and a few other things on their website at
https://freehebrew.hismagnificence.com/.
Certainly these videos seem absolutely ideal for multi-tracking with any of the textbooks out there, especially in contrast to the grammar-heavy, practise-lite nature of most (all?) of those textbooks. And I have already recommended them to people who are starting Biblical Hebrew but are a bit intimidated by learning such an unfamiliar language.