We had an overall great stay at the Marina Bay Sands. The experience of staying there and going to the famed infinity pool was a great memory. The check in process was easy enough but somewhat awkward; you meet one of his representatives who hands you the room keys. We were also told that we were given an upgraded room on a higher floor and that it would be cleaned by 330pm. We arrived at that time but the room wasn't finished being cleaned until about 415pm. I'm not sure what the inner workings are for Sun to be able to offer a room through AirBnB but aside from check in and the delay in getting the room cleaned our stay was similar to friends who booked through the hotel. He was also very responsive via messaging.