Not up to Marriott's Reputation
This hotel is most definitely not up to Marriott's standards. I booked this hotel through American Express's Fine Hotels of the World. It was anything but! Doors slamming at 6AM every morning. Several times I was promised an upgraded room (as part of American Express's arrangement with Marriott) and when I would return to the hotel that afternoon, I would be informed they gave the upgraded room to someone else. I asked several times and left several messages for the American Express liaison to contact me while I was still staying there (I was there for two weeks) and not once did he or she return my contact. My room personally was extremely small, even for Buenos Aires. The bathroom was set up in some odd configuration. Housekeeping services were spotty. The mini-bar was of course outrageously expensive. The view from my tiny room was not of Plaza San Martin but of some street. All in all, it was a mistake to spend a fortune to stay here. I have stayed at the Park Tower Buenos Aires, also on Plaza San Martin, and was treated like royalty. When I returned from my stay at the Marriott Plaza I contacted Marriott corporate and American Express. The hotel is no longer in their book of Fine Hotels of the World and Marriott corporate gave me a ton of points to apologize for the horrible stay I had. I highly advise against staying here.