I travelled to Cuba as an American nurse with all the proper documentation required by my government.
I stayed at the Nacional for 7 days and I must say that I really didn't encounter any problems.
My room was on the 6th floor. This is the Executive floor for business travellers. Room 604 had a stunning view of the Malecon and El Morro. There was a slight musty smell which I've come to expect even in the "finer" hotels in Havana. My bathroom was all white tile. It looked new and the shower had great pressure!! The water took a few minutes to get hot but once it did, it was fantastic!! I watched satellite TV which included 3 channels from China, 1 from Germany, 1 from Venusuela, 1 from Italy, 3 CNN channels, Discovery and several sports channels and the Cuban channels. Once I ordered room service. I ordered a cheeseburger and fries with ice cream and fruit. It was all very good but the hamburger seemed to be a little different. I asked if it was 100% beef and they said yes. I'm sure that they use different parts of the cow than we do in America. Just the same the taste was very good, just the texture was a little different.
The breakfast buffet was plentiful. I'm sure that if there were leftovers from dinner the night before it probably showed up on the morning buffet. I always had a few pieces of papaya and grapefriut, scrambled eggs and rice with cafe con leche and sometimes yogurt. I'd always sit at the same table in the buffet area, gazing at the people on their way to work.
The staff made the trip for me. They were all very friendly, courteous and approachable. Service was efficient and timely. The staff was very knowledgable too. I really thought the staff was wonderful and I'd recommend this hotel to anyone visiting Havana.
I ate lunch at Havana Libre cafe, very safe to eat there since the head chef is from Spain. I ate most of my dinners at paladares and at houses of friends, which is the way to experience the best of the Cuban cuisine.