Have u considered Asbury Park, NJ? Tons of condos there on the market; therefore lots of negotiating room. This year we saw great improvement on the oceanfront. Still has a way to go, but with the current activity today, buying at the right price may bring a decent return in 10 to 15 years.
So to answer your question about rental property to retire in 15-20 years... I would say, YES! Miami, as a city, is continuing to grow. We are obviously in a transitioning time right now due to high levels of inventory and many investors running for cover, but WE WILL bounce back. This is a great city to live in and will only get better with time.