Stay in South Beach but IMO you only need 1-2 days in Miami. If you have time stay up the coast towards Daytona, but that's a few hours drive. Where will you be before/after? Might be worth extending your stay there. Florida Keys and the Gulf Coast are lovely. Orlando is full of Brits driving on the wrong side of the road and pensioners driving badly (hence why the insurance and surcharge for car rental is higher in Florida than most places) ��