I'm visiting the Katy area right now, and I have made my way around to most of the sites. I opened sensorly, and was suprised by the amount of activity in Katy/southern Katy.
These are rough locations, but blue stars are some Sprint sites, and purple stars are some Verizon/At&t only sites. Its funny to see the patches of thick green where B41 is available, and then all the red where there seems to be only fringe B26.
I would be surprised if Sprint didn't have any plans to expand where the duopoly already has. If these sensorly maps have any weight, there seems to be more traffic in the Katy area than in central Houston itself.