We had a great one month stay in this place. The building is old, but the inside of the apartment is renovated with modern kitchen and bathroom. Bed was comfortable and there's also a sofa bed. The place was big and spacious enough for the two of us. The wifi is fast which made working at home easy.
The location is great, only a short stroll to the metro and bus station, to the river (where we always go for walks), grocery shops, a churrería, a local market, local cafes & restaurants, banks and pharmacies. It's also close to a nice pizza restaurant called Pizarella which we highly recommend (literally right in the corner of our street!) The host is kind and communicated well with us throughout our stay. overall we had a fantastic time and we recommend it if you wanna feel like a local in Madrid :)