Great location, literally steps away from Mannekin Pis. About 10-15 minutes walk to most of the main downtown sights. It can get a little noisy during the day with the crowd that forms around Mannekin Pis, but sometimes there's some nice music being played and it's quiet at night.
Highly recommend doing a tour when you first get there. We did a chocolate and beer tour that was great and showed us lots of local spots to check out, hidden bars, and what tourist trap places to avoid. Wish we had been able to do it our first day there. Note that a lot of places only accept cash, so be prepared for that.
The apartment was nice and clean with all the amenities you expect. My wife especially liked the towel warming rack. If/when we travel to Brussels again we would definitely stay here again.