This movie holds up. I recently rewatched and really, really enjoyed it. (Some spoilers embedded in the below.)
One thing I love about the script is how the 4 main characters give us all the different angles on the genetic dystopia problem.
Vincent is genetically "inferior", but psychologically "determined" to overcome physical limitations. He has to use his mind and body to overcome his genetics.
Jerome is genetically "superior", but psychologically defeated due to his accident causing permanent physical limitations. He has to use his mind to compensate for his body, and he "lends" his genetics to Vincent, to make Vincent as capable in their society as he once was. Vincent helps Jerome finally achieve his own potential by the end, thus the final scene.
Anton is genetically "superior", but mentally and physically weak. His willpower atrophied as he was constantly told about his genetic superiority. In a way, he allowed his genetics to act almost like an inheritance that made him soft and unambitious. Through the flashbacks, we get the sense that he was always a little cocky about his genetic superiority. He was "born into success". But through adult Anton, we learn that all he has done with his genetics is to become a conformist in this dystopian society. A rule enforcer of the genetic state itself, not someone striving for any higher purpose. When Anton loses the swim match to Vincent, he lets him go on with his plan (not shown in the script or movie), presumably because Vincent has proven that genetics alone do not determine ability, shattering one of his core beliefs.
Finally, Irene. She is genetically "upper class", but not "superior". She illustrates the degree to which genetics had become a class marker, like wealth in our current society. She is genetically strong enough to join the space exploration program, but not strong enough to be an astronaut, perhaps only a scientist. (Her last name is Cassini.) She is just as driven by passion for humanity's potential as Vincent, and just as angry about the genetic lottery. That is why they connect as they do. But, in her case, she discovers -- through Vincent's display of willpower -- that her heart condition does not have to limit the life she can lead today. Irene represents society at large, discovering that living your life under the determinism of genetics (or any other limiting class & rule system) will cause you to live a smaller life than you otherwise could.
Vincent shows us what we can aspire to despite our imperfections, and Irene shows us how to come to terms with living a happy life despite our imperfections.
"Irene" has its origin in the Greek word for "peace" (coming to terms with life as it is). Whereas "Vincent" has its origin in the Latin word for "conquer" (fighting against life's limitations and winning).