In regards to Dayton, there was a post on the Sprint Community board that read "I have been getting 4g lte in the 45417 zip. So far that's the only zip I've gotten it in".
Looks like Sprints keeping to it's "let's put towers up along the interstates" policy. I wonder when there will be LTE south of Dayton, like in the Kettering, Centerville, Mimaisburg areas?