I'm from Miami FL, and definitely recommend the Kendall area. If you get placed in Miami, the commute from FT Lauderdale or Broward County in general is not recommendable (in case anyone was wondering). It's about an hour away (on a good day) and rush hour traffic is absolutely ridiculous. Having a car in most cities can be seen as a luxury or unnecessary expense. In Miami it is borderline a necessity. I have heard nothing but bad things about the public transportation here.
The commute is not recommendable in a car because the traffic on I95 is ridiculous and people drive horrible here. My dad takes the Tri Rail and he says this is better than sitting in traffic for an hour. It's not ideal, but it works. You're right though... a car is a necessity in Florida.