We stayed at the property for two weekend nights while attending an event at a near by downtown location. I would certainly recommend this hotel for any type of trip, including even a South Beach getaway if it fits into the budget or preferences better than beach-front locations: this hotel is on the other side of the bay, but it is just a short trip to South Beach by taxi any time of day or night. By the way, it may be cheaper and easier to find a taxi on South Beach to get back to the hotel than a good parking spot.
The bay view from the rooms is nice (but it is not an ocean front type of view); the bay side sitting at the downstairs restaurant and bar is very pleasant. The restaurant itself is quite reasonable in prices and food quality. There is a full-service Publix just a short walk away and a few restaurants, so you really do not need a car to get places.
A word of caution is to check what conference would be going on during your stay. This is a conference type of a property, so there is always something on. I've stayed at hotels often enough to run into all kinds of weird gatherings, and the weekend at this Marriott was one of those occasions. The staff, however, handled the crowd exceptionally well: they had people with radios everywhere and literally managed the elevator traffic by hands to keep everyone safe and reasonably stress-free.
The rooms are typical for a downtown Marriott (small-ish); I couldn't get an upgrade with all the suites booked by the conference leads. The lounge was open for breakfast during the weekend and pretty busy but still manageable. So, overall - 5 stars for the stay; would go back anytime.