TYS is probably the nicest, cheapest area to live. Ohio would probably be miserable for someone used to California, although I don't know much about the CVG area. The one big benefit to CVG is that you can hold it right out of training and get to be a line holder sooner than anywhere else. CLT proper can be pretty expensive but there are a lot of affordable areas around it, especially across the border in SC which is still only a 10-30 minute drive to the airport depending on location.