We were in this B&B in August because we read about it on Tripadvisor and it was a great discovery.
It is placed exactly in front of the firemen station so easy to be found.
Even if it isn't in the ceter of south beach it is very near and having the parking permit you can leave nearby your car and reach walking more or less every part of the city and the beach.
The B&B has few rooms and they are quite small but there is enough space for you and your luggage but remember to ask for a room at the ground floor if you have a lot of luggage because there is no lifter.
Our room was very clean and confortable and also the small bathroom was clean and even if essential it was good enough.
The owners are very kind and can help you in finding placecs in South Beach. Their suggestions are generall very good especially for restaurants.
The breakfast is included and it changes every morning: not many things but different every day.
There is a small swimming pool that you can use more or less the whole day even if I personally find difficult to use a swimming pool having the ocean few blocks away!
It's a little bit expensive but consider that you are in South Beach and I think this is a good value for your money.