I don't know about masterpiece, but it is very good. I think this is a solid adaptation, personally. I enjoyed seeing this at the cinema last year. Yes, there are differences from the book, but so what? As long as the changes work in their own right (and they do) I don't think such things matter.

My review (if you're interested). :)

Film Review — Le Comte de Monte-Cristo (The Count of Monte Cristo) | Simon Dillon Cinema