Did we really need the third film? Weakest of the trilogy...
SPOILERS!
The BI and BS are both excellent films. I felt the continuity of the story really flowed between both movies. We have Marie in both (what an awesome girl, great chemistry between her and Bourne) and great character depth portrayed through raw emotion from the actors. I found the scene in BI when Marie finds Bourne at night watching the children silently at her step-brothers house and he says "I don't want to know who I am anymore," really powerful. Also in the BS when he confesses to Neski's daughter that he murdered her parents and that they didn't commit suicide and he says "I would want to know." It was scenes like these that made the first two movies blend really well. Both films had great substance.
Although BU was still a good film, I felt it was just a cash in from hollywood. I think it was an unnecessary sequel. And here's why;
1) Matt Damon had aged too much. He looked significantly younger in the first two films. Having flashback scenes at the lab "where it all began", that were supposed to have taken place before BI, and yet showing Damon who looked undeniably older than what he looks like in BI, irritated me because it ruined that seamless continuity of the first two films.
2) The Bourne story was wrapped up nicely at the end of BS. Bourne had cleared his name, he knew who he was, and all those behind Treadstone and the stolen CIA funds had been dealt with; Conklin, Abbott, and the corrupt Russian oil baron. Just for the purpose of cashing in; new characters like Vosen and Hirsch had to be made up because all the main villains were already dead or arrested. It seems to me strange that Vosen would never have made an appearance in BI and BS, he seemed to have just been a character written in to replace Abbott, seeing as the writers had killed him off in the second film not anticipating a third to be made.
3) The Nikki and Bourne romance. Again this hinting at Nikki having romantic feelings toward Bourne ruined the continuity of the previous films. She shows no signs of affection toward him in BI and BS.
4) The absence of Marie. I think Marie is possibly one of the best love interests ever written in film. She is such an awesome girl, down to earth, sexy, and she really looks after Bourne. You can really see how close they are from that BS scene in Goa when Bourne is complaining about his memories and Marie reassures him by saying "That is why we write them down." It was so powerful when she was murdered, you could see how broken Bourne was. I think it is sad that they try and fill the void her character's death left in BU with Nikki. Marie and Bourne were such a kick ass team. You always rooted for them.
5) The BU plot is too similar to BS; Bourne hunts corrupt CIA guys and reveals their dirty secrets. Only with new characters written in.
BU was still a good movie. I enjoyed it. But it lacked the substance and continuity of the first two films. It seemed to just be a cash cow, an unnecessary added ending to a story that was told perfectly within the first two films.