Non-stop. Cheap. Convenient.
It's not in time for our family vacation to Wisconsin this summer, but Frontier flights 814 and 815 will be flying non-stop flights between Jacksonville, FL, and Milwaukee, WI. The flights I found in September were for between $50 and $60. Other new cities have been added, too. I think I saw KC, and that would have been useful last year when I spent $350+ each time one way from JAX.
Of course, 60 Minutes says Frontier is crazy unsafe, but even if it's not perfect, my view is that the competition will at least drive down average prices at JAX. At least that's how competition is supposed to work.
Mainly, I'm glad I don't have to feel like I should drive three hours to Orlando in order to catch a three-hour flight to Milwaukee to save $100. Now it's under three hours right from JAX and just over $100 round trip. That saves about $500 round trip to visit your Uncle Harold in Wisconsin. It's so cheap you can spring for a 2-liter of Mello Yellow or RC Cola for him, especially if he's letting you shack up in the basement rec room during your visit.