Despite the rant (excuse the language) by Endre, which is definately true and describes Guillous literature in general accuracy, not just the Templar books, I quite like the books. I haven't seen the film yet (and I live in Denmark so I have no excuse), I don't think I'll see it unless someone forces me. There are very few books where the movie is worth seeing after reading the book.
The fourth book of the trilogy, "Arven efter Arn" ("Arn's Heritage?"), I read the first twenty pages then never returned to it. Without the main character it was just boring.