My husband and I booked the Mandalay Bay but were put in the nearby Delano Hotel instead, no reason given, and we had booked months ahead. Although the Delano lobby was very nice, the room looked nothing like the room at the Mandalay. It was a very long walk to the facilities of the Mandalay so we ended up not really using them.
I would not ever stay here again (our son and family who were with us and were actually at the Mandalay, picked it). Way too crowded, loud, and you have to walk through the large casino area whenever you want to eat, as all of the restaurants are around that area.