We stayed a week at Matias place and we were very happy with it. The flat was clean and has a patio. Matias rents out several rooms in his property to other guests so if you are looking for some interaction with others the place is perfect for you. We know that there is a room with balcony as well but we stayed in a different one. Matias has other flat on air bnb if this one is fully booked. Both flats are in excellent location of San Telmo district with great communication links to other parts of the city. 4 metro stations around and numerous bus links will get you anywhere you want in buenos aires. Kitchen is well equipped and the host is very responsive and helpful. Mathias gave us some very useful advice, dont forget to ask him for place to have the best steak you have ever had!
I highly recommend it to other travellers . I definitely know were i would like to stay when i return to buenos in the future
kuba and magdalena