Once again, I have no idea what you mean by halting, or "less fit" or anything else in your rambling comment. The fact that you focus on the traits you think matter, makes the comment even more idiotic. People who have no fucking clue what evolution is, should not be a part of this conversation and should be ridiculed and ignored.
Evolution is not survival of the fittest, it's natural selection. It is working on earth, on humans, and will continue to work with or without genetic engineering. Like I said, the decrease in natural genetic diversity from unchecked genetic engineering will hurt every species on earth. What we've done to cultivated plants in reducing biodiversity, should be more than enough evidence of what will happen with genetically engineered humans if we ever get there.