I haven't stayed at Dorado Beach, but I spent a week at the St. Regis in February and it was spectacular. Perhaps my new favorite luxury hotel. Service was genuine and polished, meals were very good, pool was incredible, beach was great, and it was wonderful to have access to the beach club next door - felt like two resorts in one. We stayed on property the vast majority of the time and really enjoyed every minute - pure paradise, and a great use of our Marriott points. Let me know if you have any questions about the St. Regis!