The apartment is clean, comfortable, and in a perfect location to explore Brussels! I really don’t think it could be more perfectly located, and in a lovely historical building to boot. The apartment is quite spacious as well, and really made for an excellent stay.
The only con I can think of is not specific to the apartment—for visitors not accustomed to city noise in the late hours, there is a decent amount of noise from the street. However, it really did not significantly impact our stay.