My friends and I traveled to Miami on a business trip and decided to stay at the Courtyard by Marriott Miami at the Dolphin Mall. The Marriott is beautiful with a welcoming main lobby and curtious staff. The hotel itself is located near, not walking distance, to the Dolphin Mall which is loaded with lots of restaurants and shops. I would suggest renting a car as taxi fares can be pricey when used to move from place to place. The Marriott is minutes away from the Miami Airport and playes host to large tour groups and transient visitors waiting on a flight. It is not uncommon to have the Marriott completely booked. If you happen to be there during this time, I would suggest staying clear of the lobby as it does get VERY crowded.
Renting a vehicle to facilitate moving to and from the hotel with ease.
Arriving and leaving mid-week to avoid the crowds.