I like Houston but I have only visited. If I were to live there, I would live inside the 610 loop, which has reasonable density. It is still a driving city, though.

The closest thing to a walking city are the underground tunnels downtown. However, as another commented, the downtown empties out at night; at least that was the case 20 years ago. Houston is very hot in the summer, so a walking city is probably not a reasonable thing to ask for.

One of the absurdities was the Transco tower, called today the Williams tower. It used to be the tallest building in Houston, and it is outside the 610 loop and 4 miles from the downtown. Everything around it is quite small and it is difficult to understand what economics motivated building it.

Update: I'm trying to think why I like the city. I guess it is the vegetation. Houston is perhaps a bit like how Mayan cities must have been.