This movie (I haven’t seen Infernal Affairs yet) brings me back to Boston.

Authentic Boston:

• Matt Damon and Marky Mark Wahlberg dropping their R’s for that Beantown accent.
• China Pearl.
• Massachusetts State House. I couldn’t figure out exactly where Matt Damon’s apartment was supposed to be. Beacon Hill?
• Zakim Bunker Hill Bridge.

Not Authentic Boston:

• Leonardo DiCaprio not holding his Boston accent through the whole movie.