I agree that there is a definite 50's feel to the story.  I loved the concepts and the story beats.  I was surprised a few times by the plot, which was nice, and had a lot of ideas of where it was going that turned out to be wrong.  (At one point, I thought the Federation was going to move Middleton wholly, a la Attilan, to a different planet.)  Good characters and a satisfying ending.  I'm glad I read it.