I stayed here while on a training course with the European Commission. Position-wise, it is perfect as it is conveniently located a stone's throw away from Place Schuman. You can easily get there from the airport by using the bus (12 or 21, depending what time and when you are travelling) or by train (Gare Schuman is also round the corner).
The hotel is pretty new/newly refurbished and the room I was staying in was very big. Bed was comfortable, there was plenty of room for clothes and it also contained other amenities. The bathroom had a very big walk-in shower and you could also benefit from a safe and tea/coffee if you wanted to.
Breakfast was decent enough without being brilliant and worked on a buffet basis. You could usually see a choice of pastries (sometimes more, sometimes less), cheese, ham and bread, but there were also some cereals and fresh fruit (mostly bananas and oranges).
Staff was friendly enough, although sometimes I think they should have had more than one person dealing with the front desk as they could get swamped.
The only advice I would give is that the rooms tend to go very warm and I had to sleep with the air conditioning on all night. Also, I could clearly hear the water pipes from my room on the first floor, but my colleagues who also stayed in the hotel didn't report anything similar, so maybe it was my room. There's a bar downstairs and prices are average for the area. Don't get any of the snacks, though, as they are the frozen and reheated type. The choice is also very limited, chinese rolls and samosas (which they misleadingly call 'dim sum').