The Fountainbleu is a trendy upscale hotel, it is common to see all kinds of stars staying at the hotel and the beach. It is not uncommon to see the paparazzi photographers on the beach to realize that there is some pop star or athlete around.
You need to make sure to come to the pool area early since during the summer it is usually very full. There is a second medium size adult pool, this is where many of the private parties are held. There is yet another circular pool with cabanas around it. Cabanas are available for rent, $150 and up for a day.
Service is lacking, I guess it is due to the large amount of people and stars at the hotel. If you have a car at the parking garage make sure to ask for it in advance, on busy days it can take up to 20 minutes to get it.
If you have chance visit LAPIS, the spa. It has a great long pool with whirlpools and a massage table with a very tall shower head, you can lie down and rest while water falls on your back. There is also a large nice steam bath and resting area.
If you are looking for an upscale trendy place in Miami Beach, this is the place to go.