Ocean drive is where you want to be if you do not want to deal w/ a car to get around South Beach. The Betsy has amazing beach front space & lounge chairs/umbrellas that are set up as you get there, $15 additional per/ day, but totally worth it. The pool is not much to rave about, but if you spend most of your time at the beach, this should not matter. The rooftop lounge area has an amazing view for sitting and reading, getting a massage/facial in the open air, or sipping a drink- it is not a loud music lounge area- more quiet & relaxed.
Bike rental stations are plenty near the hotel, La Sandwicherie is a few blocks away for a late- night meal or breakfast smoothie, shopping & restaurants are not a far walk either.