Out of the 4 nights I have stayed in the property, the first half were troubling, but the second half was acceptable. The top floor room I was first assigned to didn't have functional air circulation (warm humid air was expressed even if the aircon was turned to max setting). Fortunately, under the help of the hotel staff I was moved to a lower floor.
However, there was a power issue on the floor the next night and it wasn't fixed until beyond midnight. The staff member was being as helpful as they can, but there weren't enough staff to manage a separate customer issue as well as the power issue (which affected more rooms).
The room reminds me of another hotel brand which are also minimalistic in branding and services, but unfortunately my experience in Citybox Brussels has deterred me from choosing the brand in other cities, which is a shame. I do have to say I am thankful for the in-house staff which tried their best to troubleshoot things, and the room itself is fine (furniture and interior design wise) but the rooms are inconsistent in quality, so the opinions are polarizing.