I think it looks like they are just trowing up site where they can insead of waiting to lauch a whole city. My city Lincoln, NE, which is not a hick town, just popped up on the map with one tower that only reaches maybe a quarter of the city. The same in the Omaha/Council Bluffs area. I've been checking Clear coverage map almost every day for about a week after I noticed one of the small towns near me got a tower. The fastest I was able to test it was 2 mb with 2 bars.
Same thing is going on in phoenix, but when I have been areas of 4G coverage, download speeds are always good.. 8 megs down or more.