Narrated by Susan Sarandon, Secrets of the Code does a fair job of showing various points of view and although some areas of the film seem to lean more towards one side or the other, by the end, it seems to even out and give both sides of the many arguments the book seems to have spurred off.
The film really focuses on the events of the book very little. For the most point, The Da Vinci Code is only referenced to act as a segue to move onto a new focus. Instead, the documentary tries to talk to a lot of different experts on both sides of the fence about everything from who Mary Magdalene was, to if Da Vinci was really involved in any way whatsoever. The interesting thing is that all of the speakers argue that Dan Brown's book is purely fictional and it doesn't go into enough detail, but they also seem to be glad that it has created enough debate in order to get people interested in the history of the Bible and Jesus.
One of the more interesting aspects of this film, in my opinion anyway, was the segment concerning The Knights Templar and their journey to the Holy Land, as well as the segment about the other gospels that have been discovered and were not chosen to go into the Old Testament.
Most of Secrets of the Code is new data (at least new as far as Da Vinci Code documentaries are concerned). There is a bit of overlap between this documentary and others that have come out, but that is to be expected when there are a half-a-dozen similar films out there.
So should you buy/rent/see this documentary? That all depends on how passionate you are over the controversy that The Da Vinci Code has brought out into mainstream culture. If you have a strong belief on this subject (one way or the other) and you are looking for a bit more ammo the next time you get into a "passionate debate" over this book, then you should at least see Secrets of the Code. Otherwise, most likely you can skip it.