I particularly like the way we are kept guessing during the movie about her true identity. Although some of the action scenes are a little unrealistic, it is fun to feel as if we are jumping with her off one truck onto another in one scene.
Apparently, Tom Cruise didn't want the lead role and they had to change the character to a female lead to obviously suit Angelina.
Have a look at how masculine she looks in this disguise in the movie. Apparently the disguise looks very much like her brother in real life!
Enjoy the trailer - it doesn't give too much away: