I think the concept has merit, I would be curious as to how resistant it is to severe weather.

It could take the place of the "garbage patch" be built of the materials there and be safe from storms. The Sargasso Sea would work, too.

IMHO, technology of today, is far from what is really needed to build permanent floating cities of future!
Imagine, a super giant (something like 500/1000m tall on each side) floating cube etc, that is made of big & strong standard design titanium pieces (like LEGO)! (So it is unaffected by any storm or rusting etc)!
Building such cities would require invention of fusion tech first, to be able to produce truly massive amounts of titanium cheaply! (Wind & solar power etc would never be enough!)

And we will not need more than 100,000 or so of these to house the populations of the coastal cities that will be going away in the first round of sea level rise.

Reminds me of the old Sea City concept from the 1970s. http://www.aiai.ed.ac.uk/~bat/sea-city.html

I know where there are still a few parts of the Waterworld plane. Let me know if you need them.

perfect for Nebraska

I don't know if anyone at BIG realizes that the ocean being flat has no natural buffers from the winds. A storm has the potential to produce enormous swelling ocean waves that would literally create chaos for these 10,000 people, and if these habitats have no way of maneuvering out of a bad situation, all they can do is hope and wait like sitting ducks (pun intended).
This is just another example of (like western medicine) thinking that seeks to relieve the symptom instead of treating the source of the problem. It ain't likely gonna work.
Mother Nature is powerful and has little time for stupid human concepts.

I did have a big diatribe written but I erased It. Suffice to say the Titanic was unsinkable and there was no lasting damage to New Orleans after hurricane Andrew. I wonder who is paying these guys. It sure beats scamming on the internet.

Whats the prize for a dam ?