You didn't say what you want to do on vacation (or I missed it), but if it's just a beach, I wouldn't waste the drive going all the way to Miami. You could easily hit Vero Beach (or any number of beaches between Vero and Cocoa Beach). Seems to me time is at a premium here, so the less time you spend in the car, the better. Also, will you have to drive back to MCO to drop off your car and catch your return flight? If so, that's all the more reason to stay within a 150 mile radius around Orlando.

Those who said check out the Gulf coast are equally correct. St. Petersburg Beach would be a good place to check, as would some of the beaches just south of the Tampa Bay area.