TL;DR, Very happy with our stay and would stay again, there are a few considerations I will mention but none that would warrant anything less than 5 stars:
Excellent location right in the middle of Brussels, everything we wanted to see was extremely walkable. The place was comfortable, wifi worked well enough but not very strong, no A/C but some nice fans if you are feeling a little hot. Pretty quiet at night considering you are in the heart of Brussels, but it is still a busy city and there will be some amount of noise. Be prepared for some slightly steep stairs to get to the apartment, if that is something you would need to consider. Host gave lots of recommendations and information that was helpful for visiting.