We stayed here a week. As others have noted the hotel staff is exceptionally courteous and helpful. The hotel is beautiful and our room and bathroom were large, nicely decorated and kept very clean. The welcome gift was a very nice touch! The hotel's location was great for what we wanted to see; many places were in easy walking distance and a subway stop is just outside the hotel. There are a variety of restaurants near the hotel or in easy walking distance. We ate dinner at the hotel's Terrazo restaurant twice and enjoyed the good food, excellent service and great view of the Zocalo. Both times Adan did a great job. On our second visit, he mentioned that his assistant is Alex Z and the chef is Armando so we'd like to give our compliments to them as well. Once we ate breakfast at the hotel's other restaurant and it was good. My girlfriend likes fruit for breakfast and there's a fine little fruteria a block from the hotel.
I would have given the hotel 5 stars, but our room was located on the Av 16 de Septiembre. While this is a convenient pedestrianized street, it is also loud: from about 10am until 8 pm there is constant loud music and/or buskers' spiels coming from some stores. There's nothing the hotel can do about this, it's simply part of the location.
I would gladly stay here again, but would try to get a room not on that street.