The piece was very nicely done in comparison to other book adaptations that I have seen. However, while the film included many scenes that are usually not covered (e.g., Marius' conflict with his grandfather), they left out many other crucial details and key scenes. The character of Jean Valjean was covered so entirely that the other characters severely lacked in development. For example, the writing staff completely left out Eponine, who is quite possibly the most complex and most piteous (and captivating) character in the story. The Thernadiers' connection to Cosette and Gavoroche is never fully established.
Overall, I would definitely recommend you watch this adaptation, whether you've read Les Miserables or not.
Overall, I would definitely recommend you watch this adaptation, whether you've read Les Miserables or not.