This topic of genetic manipulation sounds bad, but while recognizing there could be negative unintended consequences, in some ways it's not much different than vaccines. If you could choose to have a child without defects, and was physically enhanced, this would become the new competitive standard of the human species.
Nature is the final judge of whether genetically modified folks are superior or not. Tinkering with genes opens the door to exotic defects we do not have now. Besides, stronger, faster, smarter is not always better. Neanderthals were stronger and faster than our ancestors. They lost to us because of the higher maintanence cost. They needed more calories to survive. Climate changes reduced the resources and they lost to weaker, slower but more efficient (required 1/2 -1/3 the food to survive) Homo Sapiens.