I don't agree that whole "all the islands are the same" thing. I have been to lots of different parts of the Caribbean and a lot of the islands have different feels.
Some are green and mountainous, some are flat and desert-like. Some are crowded and busy, while some are extraordinarily quiet and laid back.
I just got back from Anguilla a few weeks ago. It falls into the quiet and flat category.
Here are a few shots to warm you up for your trip...
