As much as I dislike the approach taken here, of history portrayed via reenactment (or for that matter of worthy fiction -- the Harry Potter movies were inevitable, but did this have to be?), it is very well done, and very effective in telling a story that few of us (Americans at least) heard in history classes. If you really can't read the book, which is truly great, then this is your next best option.
However, some of the historic messiness which makes the book great is lost in transition. I think it is too easy to conclude from the DVD that the abolitionist movement (and subsequent founding of Freetown) was driven almost entirely by Christian humanist zeal. That is certainly part of it, but so was finding an expedient, yet humanitarian, way to remove a population of unwanted former slaves who had fought with the British in the American Revolution from their subsequent exile to the streets of London, or to Nova Scotia.
And the DVD implies that once John Clarkson was removed from Freetown for attempting to do his job too well, the colony declined. As noble a character as Clarkson truly was, that's not quite how I remember the book. In spite of horrible management from the company in London, it seems that the new residents of Freetown were able to establish some positive connections with people of the coast and survive better for at least a while.
Finally, it is disappointing that the DVD did not include any footage of Bance Island (also called "Bunce"), an important slave trading site near Freetown. At least as of 25 years ago, Bance was a very haunted place, overgrown by cottonwood trees but unspoiled by tourist development (unlike Gorée Island is Senegal). Perhaps that is no longer so, or would the journey have been too dangerous or expensive?
Nonetheless, this is worthwhile.