I would also take language into account in this situation. In Miami you will most likely be instructed by fluent english speakers whereas in Madrid you most likely will not. I have experience of this in Madrid and found sometimes that it was hard to ask something and get a coherent response from the instructors and this I found quite annoying as you are spending quite a large chunk of change and would certainly expect a better service. That said, the odd instructor had quite good english but I personally found that most did not have a high enough level to teach a type course in english. Hey, but different strokes for different folks.