I would actually rate the inn cube at 3.5 *. It is a great location, right at the M8 entrance. When you take the escalator up from M8,the buildig in right in front. The Inn Cube is on the 10th and 11th floor (elevator only goes up to the 10th floor). I believe they have a 24 hour desk which is very helpful and enhances security.
When you check in you receive a card key (to access the floor) attached to an actual key, which is an old style lock to your room.
I was on the 11th floor, which has 9 room, but only one common toilet. In addition, there is a men's washroom (with 1 shower and 1 urinal) and a women's washroom. Despite limited number of toilets/showers, there was never a problem in getting access (perhaps they were not full). The shower pressure fluctuated between moderate and weak. The 11th floor also had a few laundry machines..
The rooms were OK, clean but on the small. There was a desk and chair in the room. The wifi signal was strong. There was no daily service, although you could exchange towels on a daily basis.
Overall, it is an very good place to stay, especially so close to the main station.