I have to say; when it came to understanding and researching the center of the Earth and the planet's contstruction for my novel, this show covered it well. The extra feature, Inside The Volcano, was a perfect bonus, (although the bonus is rather long and not as well paced owing to the time it was made).
I should point out that Patrick Steward IS on this DVD--he is in the bonus feature documentary, Inside The Volcano, produced about 1996. He is there, but not in the main feature. That's where the confusion comes from. I own it, and I recognized his voice.
Good stuff overall :)