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I think Dallas and Houston are pretty comparable. Many of the buildings share some stylistic similarities. Both cities also suffered the same fate in their downtowns... lots of of activity up through the 40s, then a near death experience in the 50s and 60s, boomtown resurgence in the 70s 80s, and now a SLOW but steady revitalization period. Both cities have very similar development patterns, so it makes sense that they look similar as well.
Los Angeles is really the original model for "sprawl metros", and since it started recovering sooner than the Texas cities, the density is much more developed there. The only big mistake in LA is that they waited so long to revive their rail transit system.