After some comparison I chose apartment P-4 in the Patriotes Residence for my stay in Brussels and I can only say: I haven't regretted my choice for a single second. The building is situated in a calm street but nevertheless very close to the Brussels city center and the European institutions as well as very easy to reach by public transport. The P-4 apartment is very well equipped and nicely decorated so you can settle in right away and feel at home. To top of my experience, I can highly recommend the Brussels-Flats team: they are very well organized, easy to communicate with and very professional.