What are the positive and negative outcomes of genetic engineering that are presented in Gattaca?

The positive outcomes are that there are "super people" who are resistant to disease. They can have whatever special traits they are designed for. I think one of the themes in the movie is that human "perfection" is largely an illusion. Even though Jerome was genetically superior, he still had human frailties. This caused him to meltdown when things did not go as planed. Human emotion cannot be genetically engineered.