I was lucky enough to see this during Chinese New Year in Malaysia. It has excellent production values, and pretty good martial arts choreography.
There are some very dark moments in the story, which came as a bit of a surprise, but are needed for Andy Lau's character to develop. Andy Lau gives an excellent performance in the lead role, and Jackie Chan's cameo is one of the best performances he has given to date, complete with a trademark fight scene.
On the negative side, Andy Lau lacks the physical prowess of his contemporaries, and supporting stars, such as Nicholas Tse and especially Wu Jing, don't really get to show off their strengths.
Well worth a look, if only for Jackie's cameo!