I have known the riflesmith in some of their videos personally for a couple decades, worked for him for a while as a machinist. He is really good, one of the best in the country, in my opinion. I have a rifle he built about 20 years ago and it still shoots great.
That being said, the one AGI video I saw, by a different gunsmith, I was specifically unimpressed with. It didn't cover everything I thought it should, and was way too basic, with not enough in-depth info for me.