This was an excellent vacation spot for small kids.
Location: There is a beach and little park just 2 blocks away with paddle board rentals, and there are two state parks on either end of the island (within walking/jogging/biking distance) that have lots of little hiking trails (forest, beach, mangroves), a light house, a nature center, bike/kayak rental, and some beautiful beach. The grocery store is within easy walking distance. The neighborhood was quiet and there are little lizards in the gardens everywhere (big + for kids!). Many attractions are within 1 hr driving distance (Everglades, Biscayne National Park), Key Largo was 1.5 hrs (still very doable).
The Condo: The Condo has a few nice features for parents. There is a little room with a trundle bed (the kids were *thrilled* about this) and a communal pool on the property. Safety-wise, the balcony has a very decent/tall wall around it, the pool is fenced, and the furniture in general is quite sturdy. There were very few knick-knacks that needed to be hidden/secured when we arrived. There are beach towels and some great beach sand toys for the kids (check the closets). Downsides: No bathtub just a shower (but the sink is large enough to wash a toddler in), and the kids bedroom has doors with glass pane on them facing the kitchen/living space, so it is hard to do anything in the common area once the kids go to sleep at night.
Other perks: The internet worked well, there is coin laundry downstairs and laundry baskets and detergent in the closet, and the parking was right out front. The kitchen had many small necessities (e.g., coffee, cooking oil, salt) as did the bathroom (sunscreen, bug spray, aloe, shampoo).