I'd like to mention my Asian-American heritage as a preface to this because it's the foundation for the enjoyment I got out of watching this movie.
This movie was originally pitched to Hollywood studios who wouldn't allow them a proper budget nor a non-white actor as the lead character (they wanted Bruce Willis and Nicolas Cage, I can't make this up, look it up), and I'm really glad they didn't take the deal.
The cast had great chemistry, the characters were memorable for the most part (would've liked a bit more depth to each of the 3 main characters), and the writing didn't feel pandering, and managed to maintain balance between humor and drama.
But most importantly, I can't tell you how refreshing it is to just watch a movie where Asian-Americans aren't highlighted for being Asian; the two Asian-American characters were written as Asian-American, and not just "Asian". They had Asian-American flaws, jokes, interests, even language.
The premise of this movie makes it easy to dismiss this as "just another Asian martial arts movie", but I promise it's got much more to it than that. This is definitely a movie I'd recommend to anyone.