I thoroughly enjoyed my stay at ST Signature. The rooms and bathrooms were clean. The check-in and check-out procedure was very smooth. The location is great; the Chinatown metro station is just a 5-minute walk. Also, there are many cafes/shops in the same lane.
The rooms might be a bit cramped for some. Since there was no window in my room, absence of natural light sometimes gave a (modern) cave-like feeling. However, if you don't plan to stay inside the room anyway and instead explore the city, this shouldn't be a major problem.