The hotel is very, very expensive compared to others, because it is the most recognized name in Havana, and Cuba makes most of it's money off tourists. If you want to stay in THE big luxury hotel in Havana, and have money to burn, this is it.
The Hotel Nacional has a gorgeous exterior and grounds, though the peacocks roaming the grounds are loud and obnoxious. The lobby is opulent, the halls are wide but plain, and the rooms are decent-sized and reasonably luxurious. But it is still Cuba, which means that the buffet breakfast is lackluster at best and inedible at worst; often I ate hard boiled eggs and guava paste wrapped in croissant dough, and that's all. There was a problem with the key card for one room out of the 15 or so in our group, which is pretty standard, but the hotel staff was utterly unable to remedy the situation for nearly an hour, which is ridiculous.
There is a safe in each room, a desk that makes change in the lobby (bring hundreds, leave most of them in the safe during the day, and each AM change your money for the day into tens and fives), and I am told there are 2 pools, though I never got to either of them. The staff in the lobby speak English.