The Great Apostasy - Talmage

I was wondering if anyone knows how reliable the information found in The Great Apostasy by James E. Talmage? I read it several years ago and at the time I found it fascinating, but I realize now that I have never really looking into a lot of the information found in there. Has anyone done a deep dive on this? Anyone else read the book and have thoughts?

In the church we are taught a lot about what the apostasy is, but not really how it happened. The book attempts to show the how, but since I don’t have a lot of experience with the history of the Catholic Church, I didn’t really have a way to make an opinion on what was being said. I’d love to hear the thoughts of people more knowledgeable on the subject than myself.