Great, central location, though on a busy street so if you want the windows open for air circulation, you'll get a lot of road noise. I was fine sleeping but it's because I brought my very effective sleepbuds for my ears. I also wouldn't want to stay here in a heatwave.
The kitchen has decent appliances but it would be hard to cook anything beyond a very basic meal as there's 1 pan, a couple of pots, nothing to serve on, if there's a colander I didn't see it, etc. So you'd be fine if you just want to do cereal, sandwiches, etc.
I was a disappointed to find that the flat as a whole was a bit on the shabby side, with the only armchair in the living room very stained, and the living room rug worn and dirty looking. The bedskirt in the master bedroom was scuffed and dirty looking, and the one of the roller shades in the master bedroom was broken, so the view of the cathedral from that bedroom was totally blocked.
The cafe directly downstairs serves lovely coffee drinks, a great quiche, and other good breakfast items. We enjoyed our stay, but if we return to Brussels would likely look elsewhere for our lodging.