According to Sprints web site
4G is not supposed to be here (Jax) yet. I live in Jax Beach and my phone is in perpetual "scanning" mode when I turn on 4G. I signed up to be notified when it is available in Jax. As for 3G coverage - seems to be solid down here. Just moved from Rochester, NY. Coverage is sketchy once you leave the city up there.
Love the phone, hate the battery life. If I could just get through a day, I would be happy. What's the point of wireless if you're constantly dragging your cords around and having to remember to plug in whenever possible? What's the point of all the cool features if, by turning them on, your phone dies in a hurry? My daughter already defected to the new BB cuz she hated her Evo...