This place is located right in the center of Brussels, two blocks away from the Grand Place and near shops, galleries, turistic spots, tours, etc. my girlfriend and I walked to every place and only used the public transport when we went to the Atomium, which is a bit outside of the city.
Dionysios (the co-host) is such a great guy. He is extremely friendly and helpful. He answers very quickly and has a very good attitude. I presume his family owns the restaurant downstairs so at the arrival we were offered a free drink.
The apartment has everything you need and is very comfortable. There are two supermarkets literally one block away in case you need everything. The only drawback is that it is a bit noisy outside because the area has a lot of bars and restos, but for me it was not a problem to get a good sleep whatsoever.
I would return to this place and I recommend it.