We just finished a 5 night award stay at the Santiago Marriott.
We were given a spacious corner room on the executive floor with amazing views of the Andes. The Concierge Lounge was on the same floor and open 24-7 for coffee and soda as well as daily breakfast 6-11a and evening cocktails 6-8p. The staff at this property were some of the best I have seen at a Marriott. They were all friendly, professional and helpful. As an example as we checked out the manager passed by and insisted on helping us with our luggage.
The Hotel is not in the city center and is primarily a business hotel, but is next to large Mall which had a wide selection of eateries. The only down side was the taxis at the hotel were about 50% higher than a regular taxi. We quickly found we could walk next door to the mall and get a taxi there.
All in all a very positive experience and we would recommend this property without reservation