The apartment is located perfect in the very hip neighbourhood of Malasana, but in a small street so it isnt noisy at all. There are plenty of nice restaurants and bars very close, so we really enjoyed it staying there.
The room is small but ok. We stayed there for 6 nights.
Luis doesnt live in the flat and rents out 4 rooms. So it can be sometimes very busy with the bathroom and kitchen. But the apartment was always very clean (!) because Luis cleand it everyday, which was top!
We had a very good stay and I would recommend it.