I stayed at Marriott Singapore last year....small/tired room, no upgrade for me (plat), small lounge, insuffiecient lounge staff (in the evening, you are supposed to wait for the staff to bring you the drink, but they are so short of staff that the wait could be quite long.) Porters asked for mandatory tips (a real turn-off for me).
It is located on a very busy/noisy corner of two main streets, and on the exit of the subway, so the hotel lobby and common areas are always crowded and noisy.