mattyboy88 speaks the truth - the traffic, humidity and women in Miami are, well, out of control.
I have made many trips to Miami since 2008 (split between the standard South Beach vacation and the calmer but still fun stay on the beach in Hollywood) and enjoy my visits. From a gambling perspective:
Gulfstream Park is a world class racetrack in Hallandale Beach and the air conditioned Silks Simulcast room is a HUGE modern race book - it rivals the largest race books in Nevada. The picture here hardly does it justice.
www.gulfstreampark.com/.../silks-simulcast
I have not been to the Seminole Hard Rock Casino although I hear good things.
You can take the Bimini Superfast boat (casino onboard) from Port Miami to Bimini (Bahamas) where they have a legal sports book. They advertise the hell out of this on ESPN Radio 790 AM The Ticket.
rwbimini.com/.../island-casino
American Airlines has 4+ daily non-stops from Miami to Las Vegas.
Naples (although quite sleepy IMO) is a 2 hour drive across the Tamiami from Miami, so if you want to be able to go to a 4-sport, world class city with a truly international airport that has many daily flights to Europe and Latin America, you are only 2 hours away.
Port St. Lucie has the beach, PGA Village (3 world-class golf courses and training facility), NY Mets Spring Training, and restaurants, but otherwise not much to do. But, its right on I-95 so you can drive down to Ft. Lauderdale/Miami in about 2 hours.