Stayed for a single night, attending a birthday party nearby. It's a short walk from the city centre but still perfectly handy for shopping etc. It's great for the bars and restaurants around Queen's in South Belfast - as the name would suggest.
No complaints (other than not getting the room until slightly after it was advertised to be ready - went to one of the nearby cafes for a bit to pass the time). Staff were very helpful, rooms were clean, well presented and well equipped. All you'd need - plus there's 24 hour food etc that I didn't try.
Will definitely stay again if I need a hotel in Belfast.