I had no idea David Bowie had a song about Homo superior, but he has always been a trend setter. It is an accurate description of man-machine melding, as the entity would be superior to unmodified humans. They will be a permanent ruling class - an objective aristocracy as they indeed are objectively superior.

If Gene Jacks cost less to produce and maintain, then our masters will prefer Gene Jacks to robots. It is all about trade-offs. One reason for mechanical workers replacing humans in certain occupation is due to cost/wage increase by government policies of child labor laws and minimum wage policies. Men, even Gene Jacked men, can perform more versatile functions, while robots tend to have extremely specified, hence limited, scope of operation.