I would fully recommend this apartment. My parents and I stayed here for a couple of weeks when visiting my brother who lives nearby.
Maria's son in law met us for check-in, he was very friendly and helpful which was very welcoming, especially after our long flight from the UK. He answered the couple of questions we had during our stay quickly and clearly. Checkout was very easy and he even helped carry our bags to the car!
The apartment itself is very nice and clean, it feels very modern and has a great view from the balcony! The building is modern and secure. The area also felt very safe and pleasant. There are a lot of bars and restaurants in the area, but it wasn't particularly noisy at night. The apartment is only a short walk to the subway so it's easy to get into the city centre. The apartment definitely contributed to a great holiday in Buenos Aires!