If we ignore the more spectacular car chase/crash, the movie is overall lesser than the 2nd, but superior to the 1st of course. It's not the best because it feels like a mere rehash, and doesn't bring much new to celebrate, despite the fact the we get to know of Bourne's past, but even that is told in some badly-made flashbacks.
The movie got camerawork and production design very similar to the 2nd movie, with similar intensity fo story, except that I got a bit bored (remember the rehashness of it). It's kinda strange because I remember praising this concluding episode as superior to the rest.
Julia Stiles should not have been given a bigger role. She is not an interesting enough actor. Even worse (worst performance in the trilogy) is the guy playing the biker assassin. Other performances are decent enough... nothing spectacular. Luckily, the last assassin here is played quite well, better than any in the series.
[sidenote] One uncomfortable aspect of this movie is that Bourne really takes too much physical punishment to continue going. It was forgiveable in the previous 2 movies, but in here it's way too much (he experiences so many heavy car crashes, and then simply walks out of then). It's sad because the series has been as close to convincing as action movies are allowed, and that added to the fun.