Terry, when faced with all we have to deal with, a bit more 'sprawl' compared to an Ultra-condensed city is actually what you want for several reasons. It has been long known since the dawn of ICBMs that DISPERSAL of industry and military units away from vulnerable fixed locations is the only way to survive a first strike! This is why a 'degree' of panic should set in these days when you hear of militaries on exercise as that 'can be' an indication of a pending attack since no military in their right mind would want to be caught flat-footed at their base... thus they mobilize. Furthermore, in the age of missiles, drones and submunissions, it is imperative that these Fielded forces actually have remote places to hunker down in - not exposed to an age of guided munitions in what has long been seen as an age called the closed battlefield.
MASS LUMPING of industries at key centers (Microsoft, silicon valley, Everett WA where all Boeing aircraft are made and so on) is exceedingly vulnerable too... Thus, industires are also seen as needing dispersed for these same reasons!
Then you have factors like Pandemics where airliners landing at all major hubs are likely to be ground zero for the rapid spread of major pandemics.
Cities are relics of the past for these reasons and more (such as 76,000 miles of underground utilities in San Fransisco alone) and thus, we need to spread these centers out, yet do it in such a way that still captures the land concious and efficiency we see in cities! Which itself can be greatly improved with 'from scratch' approaches! EVERYTHING has to be rebuilt anyway away from rivers and coasts so this is our last final chance to do it right. The EARTH could not sustain even one more incantation of modern society as it is which is so poorly built, it all has to be replaced no more than every 100 years and that's without disasters along the way!