I'm hoping to get to Cuba some day for kiting. I'm surprised to see only 3 locations discussed and frankly none of them with stellar reports that make it sound worth traveling to. The masses must be missing something, right?!?
I guess in this forum there must be many people who could give you better info than me, but since I've just coma back from a 8 days trip, I'll give you my 2 cents.
Cuba is just fantastic, not only for kiting but for enjoying the whole experience. If you've never been in Cuba, I wouldn't go there in a 5 star all-inclusive resort only to kitesurf. Much better to spend few days in Havana, or visit Vinales, Trinidad etc. AND spend some days kitesurfing.
That is why I decided to stay in the area of Playas del Este, at about 20km from La Havana. Here's a clip of a windy day (18-20 kts) at the beach, the conditions of the sea were definitley not good for a beginner, but the other days the waves were much smaller than the ones in the video.
Very few people at the beach, always no more than 5-6 kiters in the water at the same time...
This is my way, I hope you'll have the same fun I had!