I thought this movie was pretty good. It was in line with the other Doug Liman assassin/spy movies (i.e. the Bourne Identity and the Bourne Supremacy). Granted, with any of these spy films, one shouldn't expect a realistic film. It's not the reason one goes and watches any spy/assasin fare that have blockbustor tags attached to them.
The plot was not complicated, but it wasn't predictable. "Tank's" role in the whole setup was a nice little twist. The movie works mainly because of the chemistry between the Brad and Angelina. If it wasn't for that, then the movie would fall flat. The restaurant encounter, house fight, highway chase, and the final battle in the Costco Store, were all pretty intense scenes. I found out that although the film was still a spy film, the overall theme was romance.
Moreover, Vince Vaughn was very good at providing comic relief. His conversations with Brad Pitt about his mistrust of women were priceless. He said something like "they [women] all want to kill you, but most more slowly than others".
And I liked the ending. The film didn't end in some romantic/cheesy scene but right after the big gun battle at the Costco store. Moreover, it acknowledged that their marriage was working once again to some degree (i.e. they were having more sex). The open ending does leave the door open for a sequel.
The movie, though, was shorter than I expected. It did feel like they deleted or cut short some scenes. If the DVD features added scenes, I will probably rent it and maybe even buy it if there is a lot more extra added scenes.