I done JAA MCC training down in PanAm a couple of months ago. I heard great reviews about it but when I went down there was serious miss communication. One of there staff had confirmed are start date but never told the office so we showed up and they didn't know we where coming

. They put a course together at the last minute and we got a teacher who was a nice guy but didn't know much about MCC so the ground school was very poor. I did get upgraded from the 737-300 to the 800ng that was fantastic. The sim was beautiful but again the instructors in the sim didn't know anything about the course or what was going on. Do it at your own risk but they seemed very unprofessional to me, serious lack of communication.
Hope this helps , good luck