I love the first three Bourne movies. They are fantastic.
The Bourne Legacy is the red-headed stepchild of the family.
Tony Gilroy's third time stepping behind the camera (he also directed Duplicity and Michael Clayton) is by and large a failure. That is due in large part to the standard that Gilroy helped set with the first three films, as he wrote the screenplays, but here, without Jason Bourne at its center, the film never really gets off the ground. So much time is spent establishing the separate origins and situational jeopardy of Aaron Cross (Renner as our new left-for-dead super soldier) and Dr. Marta Shearing (Rachel Weisz as our new imperiled love interest whose companionship is at first a begrudging one but eventually love grows from it) that it would have to be particularly compelling to not disengage the audience. Alas, it is not and it does.
The tension that is so masterfully built and maintained in the previous entrants in the series is not maintained here. The action sequences are serviceable, but ultimately they are too few and too far between. The black ops mumbo-jumbo was relatively follow-able, but its domination of the dialogue made an emotional connection with the film something of an uphill struggle. Aaron Cross and Marta Shearing are interesting enough characters that the potential fifth film in the series with a teaming up of Cross with Jason Bourne would probably rekindle my interest in the series going forward, but it would require something significant being added back to the mix (Matt Damon or Paul Greengrass) to inspire any hope going forward. Given The Bourne Legacy's fairly strong returns at the box office, perhaps that is a scenario that plays out, but until then, the series has ended on a down-note.