Didn't like it as much as "The Da Vinci Code", but enjoyed the book a far sight more than "Angels & Demons". I will say, though, that I thought "Angels & Demons" was a decent (heavy on the action) movie and I imagine "The Lost Symbol" will be a pretty good and similarly crazy fast-paced movie.
As to the need to read the book rather than just wait for the film... eh, lots of other good books out there in my opinion.
