It's not nearly as bad as the other critics are saying. The music is really good, and the editing (except for one part) is exceptionally good. I really liked the non-linear storytelling, and Jude Law's performance is amazing. It helped knowing it was adapted from a graphic novel going into it. If you liked Timeline and you didn't hate Guy Richie's previous Sherlock Holmes movies, I think you'll really like this.
King Arthur: Legend of the Sword - 4/5