We stayed at the Carlos V for four nights and found it a very good value. The rooms are small, but very clean and quite adequate. I had read reviews on this site about noise from the street so we asked for a room away from Preciados (the busy pedestrian street at the front of the hotel. We had no noise problems whatsoever.
Some tips: the hotel has a beautiful dining room but we only used it for happy hour (two drinks for the price of one) as you can get a less expensive breakfast within a block or two of the hotel (try Pans). The only small thing that bothered me about the stay was that the hotel literature in the room said you could get "complimentry coffee" by calling the front desk. The front desk told us to call room service to ask for the coffee, but when the coffee came we had to pay a "service charge." It was not a lot of money, but just sort of cheesy for them to give you "free" coffee while you still had to pay a fee for getting it. Other than that very small thing we enjoyed the hotel and highly recommend it.









