Hi there.
We flew into Miami and spent 2 nights there before going up to Orlando, then spent 3 nights there before coming home.
We absolutely fell in love with Miami Beach and have vowed to return!
We stayed on the North part of Ocean Drive in a small hotel called 'The Penguin'. It didn't have a pool which was our sole 'grumble' with it, but over the street is the ocean so you can't really call it a grumble as such!
Our son is 5 and he was more than happy to be on the beach with a bucket and spade. The sea was pretty shallow for quite a way out too which was a bonus. There was a play park a little way up Ocean Drive which was frequented daily after the exertions of sunning ourselves!
On Wednesday we had to check out of our room by 11am but our flight wasn't until 8pm, so we were left wondering what to do with ourselves and our 5 (!) suitcases. We happened upon a flyer that advertised 'Miami Childrens Museum' which was en route to the airport anyway (just over the Mcarthur causeway) and we toddled off to it. It was amazing! We lost a good 3 hours here including having some lunch. Over the road from the museum was something called the Parrot Trail which may (or may not!) have been a zoo/animal type thing.
There's also a 'seaquarium' but we didn;'t get chance to go.
I definitely vote for Miami. There really is loads to do, it's a very 'trendy' place but the mix of people is so ecclectic, I certainly didn't feel out of place being chunky, 30 and one who dresses for comfort rather than fashion!