This apartment is extremely nice - it's huge and more than comfortable for 2-6 people. Modern, nice decoration, spacious, super clean. Had everything we needed.
Sadly, the major negative point for me personally was the neighbourhood/surroundings. I understand this has nothing to do with the apartment itself, but with Brussels. I would do a bit more research before and see if you'd feel comfortable staying in this type of neighbourhood which at times, for two women travelling alone, didn't feel safe and it's quite dirty. Connections to the city centre are still fairly good, but prepare to walk long blocks uphill/downhill. Public transport is ok but not super convenient at all times. We mostly walked so that's why the surroundings did affect our experience.
Otherwise, the host is very helpful and didn't have any issues during my stay. The shower temperature and pressure are great, the beds are very comfortable, the apartment is warm in winter and not noisy. Modern building w/ elevator.