Miami is Miami because of LOCATION - right on the warm tropical waters of the Atlantic Ocean. Because of that, it's a superstar. So, people with money want to be there and be seen. It also has a massive influx of immigrants from Cuba/Latin America who want to succeed financially. (Some by illicit means...). Thus, it's highly competitive.
But competition isn't everything. I'm sure Jax has the edge in terms of hospitality, friendliness, family stability, peacefulness.