If you are looking for a relatively inexpensive place to stay for one or a few nights and you are okay with a very small room with only the basic necessities then the CABINN Metro is a solid choice. It general it was clean, comfortable for my two night stay.
Pros: Convenient to the rail and metro; easy to access from CPH airport; a short 10 minute walk to the Bella Convention Center; very walkable area and the Fields Shopping mall is a two minute walk with a large selection of stores and restaurants; clean comfortable bed; convenient breakfast area; comfortable open lobby areas; good wifi connectivity; an electric kettle with some instant coffee/tea and flat screen, and a very small writing desk and chair, adequate electric plugs, night stand, small clothes hanging space rounded out the tight space.
Cons: I had a standard room which was very small; it was very warm with only a small window for air; the front desk did provide a small fan which helped, but it was uncomfortable in the room at times, I opted to work in the adjacent lobby area which was cooled; the bathroom/shower is very cramped single space with a draw curtain making it even tighter; entire space gets wet so once you shower, using the bathroom is problematic till it dries out a bit.
Overall, for a one or two night stay I would consider staying there again if I needed to be near the Bella Center.