I give it an 8 or 9. It was everything I was hoping to get from a Han Solo origin story. Great action, surprises, and excellent story of space scoundrels with hints at what made Han who he is.
The actors were fantastic, especially the young actors who played Han and Lando, I never once thought to myself during the movie that they were not Han and Lando. In fact I was quite impressed at how they captured their characters, and the story overall was true to the characters.