Christian has a great place! It is not just clean, but immaculate, within walking distance of the best Brussels has to offer, and Christian was easy to communicate with. I would absolutely stay here again. His check-in information made it very easy to get into the apartment. (Automatic lock!)
The only downside was the "stairs of death" that need to be climbed between levels. The apartment is older, which means a lot of charm, but that also means the stairs can be a hassle to climb. If you have issues with mobility, struggle on modern stairs, or have a lot of heavy luggage, I would recommend bringing an assistant.