Check in was automatic, with clear instructions received via email. The apartment corresponds to the description. The bathroom doesn't allow much privacy as the shower only has a glass door and the toiled door can't be closed when you sit on it.
The walls are thin and our neighbours upstairs were loud, but I think it depends on who is occupying that apartment during your stay. Apart from that, the position is great, so I would recommend this place, especially if you plan to walk around Brussels a lot.