Best overall HH property near MIA airport is Hampton Inn - South on 57th ( Red road) newish property, free HS internet, secured parking lot and free shuttle to airport (10 mins at best) I always get an upgrade to a suite there.
Rates often in the $60 to $70 range.
The Hilton Miami ( just around the corner from the HI and ES) charges for parking, the lounge doesnt open until 630AM and has a somewhat worn feel to it.
mike