I responded thus

• everittdmickey · 4 hours ago
  Robin Hanson is a pretty smart guy. I knew him back when on the Extropian Mailing list. We had a few words.
  I believe that he is wrong about the megacities...Virtual Reality eliminates their need.
  I also question EM...consider an augmented human instead.
  cybernetic plug ins anyone?

In addition I might point out that nanotech, machine phase assemblers, the block chain, and 3D printing are wildcards that no one had considered until just recently.

The Future isn't what it used to be.

I direct your attention to it. You may be interested